The BEER algorithm identified Kepler-76b, a hot Jupiter orbiting an F star, from its Kepler light curve. The light curve showed evidence of the beaming, ellipsoidal, and reflection effects consistent with a planetary companion. Follow-up spectroscopy confirmed Kepler-76b with a mass of 2.0 ± 0.26 MJup and orbital period of 1.5449 days. Analysis of the light curve effects provided evidence that Kepler-76b exhibits atmospheric superrotation, or an eastward jet stream that shifts the hottest atmospheric region.
First identification of_direct_collapse_black_holes_candidates_in_the_early_u...Sérgio Sacani
The first black hole seeds, formed when the Universe was younger than ⇠ 500Myr, are recognized
to play an important role for the growth of early (z ⇠ 7) super-massive black holes.
While progresses have been made in understanding their formation and growth, their observational
signatures remain largely unexplored. As a result, no detection of such sources has been
confirmed so far. Supported by numerical simulations, we present a novel photometric method
to identify black hole seed candidates in deep multi-wavelength surveys.We predict that these
highly-obscured sources are characterized by a steep spectrum in the infrared (1.6−4.5μm),
i.e. by very red colors. The method selects the only 2 objects with a robust X-ray detection
found in the CANDELS/GOODS-S survey with a photometric redshift z & 6. Fitting their
infrared spectra only with a stellar component would require unrealistic star formation rates
(& 2000M# yr−1). To date, the selected objects represent the most promising black hole seed
candidates, possibly formed via the direct collapse black hole scenario, with predicted mass
> 105M#. While this result is based on the best photometric observations of high-z sources
available to date, additional progress is expected from spectroscopic and deeper X-ray data.
Upcoming observatories, like the JWST, will greatly expand the scope of this work.
Detection of lyman_alpha_emission_from_a_triply_imaged_z_6_85_galaxy_behind_m...Sérgio Sacani
We report the detection of Ly emission at 9538A
in the Keck/DEIMOS and HST WFC3
G102 grism data from a triply-imaged galaxy at z = 6:846 0:001 behind galaxy cluster MACS
J2129.4 0741. Combining the emission line wavelength with broadband photometry, line ratio upper
limits, and lens modeling, we rule out the scenario that this emission line is [O II] at z = 1:57. After
accounting for magnication, we calculate the weighted average of the intrinsic Ly luminosity to be
1:31042 erg s 1 and Ly equivalent width to be 7415A. Its intrinsic UV absolute magnitude at
1600A
is 18:60:2 mag and stellar mass (1:50:3)107 M, making it one of the faintest (intrinsic
LUV 0:14 L
UV) galaxies with Ly detection at z 7 to date. Its stellar mass is in the typical range
for the galaxies thought to dominate the reionization photon budget at z & 7; the inferred Ly escape
fraction is high (& 10%), which could be common for sub-L z & 7 galaxies with Ly emission. This
galaxy oers a glimpse of the galaxy population that is thought to drive reionization, and it shows
that gravitational lensing is an important avenue to probe the sub-L galaxy population.
Detection of solar_like_oscillations_in_relies_of_the_milk_way_asteroseismolo...Sérgio Sacani
Asteroseismic constraints on K giants make it possible to infer radii, masses and ages of tens
of thousands of field stars. Tests against independent estimates of these properties are however
scarce, especially in the metal-poor regime. Here, we report the detection of solar-like
oscillations in 8 stars belonging to the red-giant branch and red-horizontal branch of the globular
cluster M4. The detections were made in photometric observations from the K2 Mission
during its Campaign 2. Making use of independent constraints on the distance, we estimate
masses of the 8 stars by utilising different combinations of seismic and non-seismic inputs.
When introducing a correction to the Δν scaling relation as suggested by stellar models, for
RGB stars we find excellent agreement with the expected masses from isochrone fitting, and
with a distance modulus derived using independent methods. The offset with respect to independent
masses is lower, or comparable with, the uncertainties on the average RGB mass
(4 − 10%, depending on the combination of constraints used). Our results lend confidence to
asteroseismic masses in the metal poor regime. We note that a larger sample will be needed
to allow more stringent tests to be made of systematic uncertainties in all the observables
(both seismic and non-seismic), and to explore the properties of RHB stars, and of different
populations in the cluster.
The canarias einstein_ring_a_newly_discovered_optical_einstein_ringSérgio Sacani
We report the discovery of an optical Einstein Ring in the Sculptor constellation,
IAC J010127-334319, in the vicinity of the Sculptor Dwarf Spheroidal Galaxy. It is
an almost complete ring ( 300◦) with a diameter of 4.5 arcsec. The discovery was
made serendipitously from inspecting Dark Energy Camera (DECam) archive imaging
data. Confirmation of the object nature has been obtained by deriving spectroscopic
redshifts for both components, lens and source, from observations at the 10.4 m Gran
Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive
early-type galaxy, has a redshift of z = 0.581 while the source is a starburst galaxy
with redshift of z = 1.165. The total enclosed mass that produces the lensing effect
has been estimated to be Mtot = (1.86 ± 0.23) · 1012M⊙.
First identification of_direct_collapse_black_holes_candidates_in_the_early_u...Sérgio Sacani
The first black hole seeds, formed when the Universe was younger than ⇠ 500Myr, are recognized
to play an important role for the growth of early (z ⇠ 7) super-massive black holes.
While progresses have been made in understanding their formation and growth, their observational
signatures remain largely unexplored. As a result, no detection of such sources has been
confirmed so far. Supported by numerical simulations, we present a novel photometric method
to identify black hole seed candidates in deep multi-wavelength surveys.We predict that these
highly-obscured sources are characterized by a steep spectrum in the infrared (1.6−4.5μm),
i.e. by very red colors. The method selects the only 2 objects with a robust X-ray detection
found in the CANDELS/GOODS-S survey with a photometric redshift z & 6. Fitting their
infrared spectra only with a stellar component would require unrealistic star formation rates
(& 2000M# yr−1). To date, the selected objects represent the most promising black hole seed
candidates, possibly formed via the direct collapse black hole scenario, with predicted mass
> 105M#. While this result is based on the best photometric observations of high-z sources
available to date, additional progress is expected from spectroscopic and deeper X-ray data.
Upcoming observatories, like the JWST, will greatly expand the scope of this work.
Detection of lyman_alpha_emission_from_a_triply_imaged_z_6_85_galaxy_behind_m...Sérgio Sacani
We report the detection of Ly emission at 9538A
in the Keck/DEIMOS and HST WFC3
G102 grism data from a triply-imaged galaxy at z = 6:846 0:001 behind galaxy cluster MACS
J2129.4 0741. Combining the emission line wavelength with broadband photometry, line ratio upper
limits, and lens modeling, we rule out the scenario that this emission line is [O II] at z = 1:57. After
accounting for magnication, we calculate the weighted average of the intrinsic Ly luminosity to be
1:31042 erg s 1 and Ly equivalent width to be 7415A. Its intrinsic UV absolute magnitude at
1600A
is 18:60:2 mag and stellar mass (1:50:3)107 M, making it one of the faintest (intrinsic
LUV 0:14 L
UV) galaxies with Ly detection at z 7 to date. Its stellar mass is in the typical range
for the galaxies thought to dominate the reionization photon budget at z & 7; the inferred Ly escape
fraction is high (& 10%), which could be common for sub-L z & 7 galaxies with Ly emission. This
galaxy oers a glimpse of the galaxy population that is thought to drive reionization, and it shows
that gravitational lensing is an important avenue to probe the sub-L galaxy population.
Detection of solar_like_oscillations_in_relies_of_the_milk_way_asteroseismolo...Sérgio Sacani
Asteroseismic constraints on K giants make it possible to infer radii, masses and ages of tens
of thousands of field stars. Tests against independent estimates of these properties are however
scarce, especially in the metal-poor regime. Here, we report the detection of solar-like
oscillations in 8 stars belonging to the red-giant branch and red-horizontal branch of the globular
cluster M4. The detections were made in photometric observations from the K2 Mission
during its Campaign 2. Making use of independent constraints on the distance, we estimate
masses of the 8 stars by utilising different combinations of seismic and non-seismic inputs.
When introducing a correction to the Δν scaling relation as suggested by stellar models, for
RGB stars we find excellent agreement with the expected masses from isochrone fitting, and
with a distance modulus derived using independent methods. The offset with respect to independent
masses is lower, or comparable with, the uncertainties on the average RGB mass
(4 − 10%, depending on the combination of constraints used). Our results lend confidence to
asteroseismic masses in the metal poor regime. We note that a larger sample will be needed
to allow more stringent tests to be made of systematic uncertainties in all the observables
(both seismic and non-seismic), and to explore the properties of RHB stars, and of different
populations in the cluster.
The canarias einstein_ring_a_newly_discovered_optical_einstein_ringSérgio Sacani
We report the discovery of an optical Einstein Ring in the Sculptor constellation,
IAC J010127-334319, in the vicinity of the Sculptor Dwarf Spheroidal Galaxy. It is
an almost complete ring ( 300◦) with a diameter of 4.5 arcsec. The discovery was
made serendipitously from inspecting Dark Energy Camera (DECam) archive imaging
data. Confirmation of the object nature has been obtained by deriving spectroscopic
redshifts for both components, lens and source, from observations at the 10.4 m Gran
Telescopio CANARIAS (GTC) with the spectrograph OSIRIS. The lens, a massive
early-type galaxy, has a redshift of z = 0.581 while the source is a starburst galaxy
with redshift of z = 1.165. The total enclosed mass that produces the lensing effect
has been estimated to be Mtot = (1.86 ± 0.23) · 1012M⊙.
Evidence for the_thermal_sunyaev-zeldovich_effect_associated_with_quasar_feed...Sérgio Sacani
Using a radio-quiet subsample of the Sloan Digital Sky Survey spectroscopic quasar
catalogue, spanning redshifts 0.5–3.5, we derive the mean millimetre and far-infrared
quasar spectral energy distributions (SEDs) via a stacking analysis of Atacama Cosmology
Telescope and Herschel-Spectral and Photometric Imaging REceiver data. We
constrain the form of the far-infrared emission and find 3σ–4σ evidence for the thermal
Sunyaev-Zel’dovich (SZ) effect, characteristic of a hot ionized gas component with
thermal energy (6.2 ± 1.7) × 1060 erg. This amount of thermal energy is greater than
expected assuming only hot gas in virial equilibrium with the dark matter haloes of
(1 − 5) × 1012h
−1M that these systems are expected to occupy, though the highest
quasar mass estimates found in the literature could explain a large fraction of this
energy. Our measurements are consistent with quasars depositing up to (14.5±3.3) τ
−1
8
per cent of their radiative energy into their circumgalactic environment if their typical
period of quasar activity is τ8 × 108 yr. For high quasar host masses, ∼ 1013h
−1M,
this percentage will be reduced. Furthermore, the uncertainty on this percentage is
only statistical and additional systematic uncertainties enter at the 40 per cent level.
The SEDs are dust dominated in all bands and we consider various models for dust
emission. While sufficiently complex dust models can obviate the SZ effect, the SZ
interpretation remains favoured at the 3σ–4σ level for most models.
Exocometary gas in_th_hd_181327_debris_ringSérgio Sacani
An increasing number of observations have shown that gaseous debris discs are not an
exception. However, until now we only knew of cases around A stars. Here we present the first
detection of 12CO (2-1) disc emission around an F star, HD 181327, obtained with ALMA
observations at 1.3 mm. The continuum and CO emission are resolved into an axisymmetric
disc with ring-like morphology. Using a Markov chain Monte Carlo method coupled with
radiative transfer calculations we study the dust and CO mass distribution. We find the dust is
distributed in a ring with a radius of 86:0 0:4 AU and a radial width of 23:2 1:0 AU. At
this frequency the ring radius is smaller than in the optical, revealing grain size segregation
expected due to radiation pressure. We also report on the detection of low level continuum
emission beyond the main ring out to 200 AU. We model the CO emission in the non-LTE
regime and we find that the CO is co-located with the dust, with a total CO gas mass ranging
between 1:2 10 6 M and 2:9 10 6 M, depending on the gas kinetic temperature and
collisional partners densities. The CO densities and location suggest a secondary origin, i.e.
released from icy planetesimals in the ring. We derive a CO cometary composition that is
consistent with Solar system comets. Due to the low gas densities it is unlikely that the gas is
shaping the dust distribution.
We report the discovery of a new Kepler transiting circumbinary planet (CBP).
This latest addition to the still-small family of CBPs defies the current trend of known
short-period planets orbiting near the stability limit of binary stars. Unlike the previous
discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has
a very long orbital period ( 1100 days) and was at conjunction only twice during
the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-
1647b is not only the longest-period transiting CBP at the time of writing, but also one
of the longest-period transiting planets. With a radius of 1:060:01 RJup it is also the
largest CBP to date. The planet produced three transits in the light-curve of Kepler-
1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the
times of the stellar eclipses, allowing us to measure its mass to be 1:520:65 MJup.
The planet revolves around an 11-day period eclipsing binary consisting of two Solarmass
stars on a slightly inclined, mildly eccentric (ebin = 0:16), spin-synchronized
orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is
in the conservative habitable zone of the binary star throughout its orbit.
Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of
1011.5 K. Relativistic boosting can increase its observed value, but apparent brightness temperatures
much in excess of 1013 K are inaccessible using ground-based very long baseline interferometry (VLBI)
at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission
RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as
small as 26 µas (2.7 light months) and brightness temperature in excess of 1013 K. These measurements
challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive
black holes and require a much higher Doppler factor than what is determined from jet apparent
kinematics.
Keywords: galaxies: active — galaxies: jets — radio continuum: galaxies — techniques: interferometric
— quasars: individual (3C 273)
A nearby yoiung_m_dwarf_with_wide_possibly_planetary_m_ass_companionSérgio Sacani
O objeto de massa planetária J2126, anteriormente pensado como sendo um planeta solitário, orbita sua estrela mãe na maior órbita já descoberta até agora no universo, de acordo com uma equipe de astrônomos liderada pelo Dr. Niall Deacon, da Universidade de Hertfordshire, no Reino Unido.
O J2126, cujo nome completo é 2MASS J21265040-8140293, tem cerca de 13 vezes a massa de Júpiter.
Sua órbita é de aproximadamente 6900 Unidades Astronômicas de distância da sua estrela, a TYC 9486-927-1, uma estrela ativa, de rotação rápida e classificada como sendo do tipo Anã-M.
Essa é uma órbita 6900 vezes maior que a distância da Terra ao Sol, ou seja, aproximadamente 1 trilhão de quilômetros. Nessa sua órbita, o planeta leva 900000 anos para completar uma volta ao redor da sua estrela.
Supermassive black holes in galaxy centres can grow by the accretion
of gas, liberating enormous amounts of energy that might
regulate star formation on galaxy-wide scales1–3
. The nature of
gaseous fuel reservoirs that power black hole growth is nevertheless
largely unconstrained by observations, and is instead routinely
simplified as a smooth, spherical inflow of very hot gas
in accordance with the Bondi solution4
. Recent theory5–7 and
simulations8–10 instead predict that accretion can be dominated by
a stochastic, clumpy distribution of very cold molecular clouds,
though unambiguous observational support for this prediction remains
elusive. Here we show observational evidence for a cold,
clumpy accretion flow toward a supermassive black hole fuel reservoir
in the nucleus of the Abell 2597 Brightest Cluster Galaxy
(BCG), a nearby (z = 0.0821) giant elliptical galaxy surrounded
by a dense halo of hot plasma11–13. Under the right conditions,
thermal instabilities can precipitate from this hot gas, producing a
rain of cold clouds that fall toward the galaxy’s centre14, sustaining
star formation amid a kiloparsec-scale molecular nebula that inhabits
its core15. New interferometric sub-millimetre observations
show that these cold clouds also fuel black hole accretion, revealing
“shadows” cast by molecular clouds as they move inward at ∼ 300
km s−1
toward the active supermassive black hole in the galaxy
centre, which serves as a bright backlight. Corroborating evidence
from prior observations16 of warmer atomic gas at extremely high
spatial resolution17, along with simple arguments based on geometry
and probability, indicates that these clouds are within the innermost
hundred parsecs of the black hole, and falling closer toward
it
We discovered two transient events in the Kepler eld with light curves that strongly suggest they
are type II-P supernovae. Using the fast cadence of the Kepler observations we precisely estimate
the rise time to maximum for KSN2011a and KSN2011d as 10.50:4 and 13.30:4 rest-frame days
respectively. Based on ts to idealized analytic models, we nd the progenitor radius of KSN2011a
(28020 R) to be signicantly smaller than that for KSN2011d (49020 R) but both have similar
explosion energies of 2.00:3 1051 erg.
The rising light curve of KSN2011d is an excellent match to that predicted by simple models of
exploding red supergiants (RSG). However, the early rise of KSN2011a is faster than the models
predict possibly due to the supernova shockwave moving into pre-existing wind or mass-loss from the
RSG. A mass loss rate of 10 4 M yr 1 from the RSG can explain the fast rise without impacting
the optical
ux at maximum light or the shape of the post-maximum light curve.
No shock breakout emission is seen in KSN2011a, but this is likely due to the circumstellar inter-
action suspected in the fast rising light curve. The early light curve of KSN2011d does show excess
emission consistent with model predictions of a shock breakout. This is the rst optical detection of
a shock breakout from a type II-P supernova.
A 2 4_determination_of_the_local_value_of_the_hubble_constantSérgio Sacani
We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to
reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%.
The bulk of this improvement comes from new, near-infrared observations of Cepheid
variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling
the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these
in turn leverage the magnitude-redshift relation based on 300 SNe Ia at z <0.15. All
19 hosts as well as the megamaser system NGC4258 have been observed with WFC3
in the optical and near-infrared, thus nullifying cross-instrument zeropoint errors in the
relative distance estimates from Cepheids. Other noteworthy improvements include a
33% reduction in the systematic uncertainty in the maser distance to NGC4258, a larger
sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to
the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of
Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW)
Cepheids.
Magnetic interaction of_a_super_cme_with_the_earths_magnetosphere_scenario_fo...Sérgio Sacani
Solar eruptions, known as Coronal Mass Ejections (CMEs), are
frequently observed on our Sun. Recent Kepler observations of super
ares
on G-type stars have implied that so called super-CMEs, possessing kinetic
energies 10 times of the most powerful CME event ever observed on the Sun,
could be produced with a frequency of 1 event per 800-2000 yr on solar-
like slowly rotating stars. We have performed a 3D time-dependent global
magnetohydrodynamic simulation of the magnetic interaction of such a CME
cloud with the Earth's magnetosphere. We calculated the global structure
of the perturbed magnetosphere and derive the latitude of the open-closed
magnetic eld boundary. We also estimated energy
uxes penetrating the
Earth's ionosphere and discuss the consequences of energetic particle
uxes
on biological systems on early Earth.
Young remmants of_type_ia_supernovae_and_their_progenitors_a_study_of_snr_g19_03Sérgio Sacani
Type Ia supernovae, with their remarkably homogeneous light curves and spectra, have been used as
standardizable candles to measure the accelerating expansion of the Universe. Yet, their progenitors
remain elusive. Common explanations invoke a degenerate star (white dwarf) which explodes upon
reaching close to the Chandrasekhar limit, by either steadily accreting mass from a companion star
or violently merging with another degenerate star. We show that circumstellar interaction in young
Galactic supernova remnants can be used to distinguish between these single and double degenerate
progenitor scenarios. Here we propose a new diagnostic, the Surface Brightness Index, which can
be computed from theory and compared with Chandra and VLA observations. We use this method
to demonstrate that a double degenerate progenitor can explain the decades-long
ux rise and size
increase of the youngest known Galactic SNR G1.9+0.3. We disfavor a single degenerate scenario.
We attribute the observed properties to the interaction between a steep ejecta prole and a constant
density environment. We suggest using the upgraded VLA to detect circumstellar interaction in
the remnants of historical Type Ia supernovae in the Local Group of galaxies. This may settle the
long-standing debate over their progenitors.
Subject headings: ISM: supernova remnants | radio continuum: general | X-rays: general | bi-
naries: general | circumstellar matter | supernovae: general | ISM: individual
objects(SNR G1.9+0.3)
Quase 900 galáxias próximas, porém escondidas, têm sido estudadas por uma equipe internacional de astrônomos, levando uma nova luz sobre o entendimento do Grande Atrator - uma concentração difusa de massa a 250 milhões de anos-luz de distância, que está puxando a nossa Via Láctea, e milhares de outras galáxias em sua direção.
Usando o Multibeam Receiver, instalado no rádio telescópio Parkes de 64 m, pertencente à instituição CSIRO na Austrália, a equipe foi capaz de ver através das estrelas e da poeira da nossa galáxia, vasculhando assim uma região inexplorada do espaço, conhecida pelos astrônomos como Zone of Avoidance (Zona de Anulação).
“Nós descobrimos 883 galáxias, um terço das quais nunca tinham sido vistas anteriormente”, disse o Professor Lister Staveley-Smith, membro da equipe, do ARC Centre of Excellence for All-sky Astrophysics, e da University of Western Australia, um dos nós do International Centre for Radio Astronomy Research.
EXTINCTION AND THE DIMMING OF KIC 8462852Sérgio Sacani
To test alternative hypotheses for the behavior of KIC 8462852, we obtained measurements of the star
over a wide wavelength range from the UV to the mid-infrared from October 2015 through December
2016, using Swift, Spitzer and at AstroLAB IRIS. The star faded in a manner similar to the longterm
fading seen in Kepler data about 1400 days previously. The dimming rate for the entire period
reported is 22.1 ± 9.7 milli-mag yr−1
in the Swift wavebands, with amounts of 21.0 ± 4.5 mmag in
the groundbased B measurements, 14.0 ± 4.5 mmag in V , and 13.0 ± 4.5 in R, and a rate of 5.0 ± 1.2
mmag yr−1 averaged over the two warm Spitzer bands. Although the dimming is small, it is seen at
& 3 σ by three different observatories operating from the UV to the IR. The presence of long-term
secular dimming means that previous SED models of the star based on photometric measurements
taken years apart may not be accurate. We find that stellar models with Tef f = 7000 - 7100 K and
AV ∼ 0.73 best fit the Swift data from UV to optical. These models also show no excess in the
near-simultaneous Spitzer photometry at 3.6 and 4.5 µm, although a longer wavelength excess from
a substantial debris disk is still possible (e.g., as around Fomalhaut). The wavelength dependence of
the fading favors a relatively neutral color (i.e., RV & 5, but not flat across all the bands) compared
with the extinction law for the general ISM (RV = 3.1), suggesting that the dimming arises from
circumstellar material
Periodic mass extinctions_and_the_planet_x_model_reconsideredSérgio Sacani
The 27 Myr periodicity in the fossil extinction record has been con-
firmed in modern data bases dating back 500 Myr, which is twice the time
interval of the original analysis from thirty years ago. The surprising regularity
of this period has been used to reject the Nemesis model. A second
model based on the sun’s vertical galactic oscillations has been challenged
on the basis of an inconsistency in period and phasing. The third astronomical
model originally proposed to explain the periodicity is the Planet
X model in which the period is associated with the perihelion precession
of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated
to mass extinctions, a trans-Neptunian super-Earth planet has been proposed
to explain the observation that the inner Oort cloud objects Sedna
and 2012VP113 have perihelia that lie near the ecliptic plane. In this
Letter we reconsider the Planet X model in light of the confluence of the
modern palaeontological and outer solar system dynamical evidence.
Key Words: astrobiology - planets and satellites - Kuiper belt:
general - comets: general
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grainsSérgio Sacani
Os astrónomos usaram o ALMA e os telescópios do IRAM para fazer a primeira medição direta da temperatura dos grãos de poeira grandes situados nas regiões periféricas de um disco de formação planetária que se encontra em torno de uma estrela jovem. Ao observar de forma inovadora um objeto cujo nome informal é Disco Voador, os astrónomos descobriram que os grãos de poeira são muito mais frios do que o esperado: -266º Celsius. Este resultado surpreendente sugere que os modelos teóricos destes discos precisam de ser revistos.
Uma equipa internacional liderada por Stephane Guilloteau do Laboratoire d´Astrophysique de Bordeaux, França, mediu a temperatura de enormes grãos de poeira que se encontram em torno da jovem estrela 2MASS J16281370-2431391 na região de formação estelar Rho Ophiuchi, a cerca de 400 anos-luz de distância da Terra.
Esta estrela encontra-se rodeada por um disco de gás e poeira — chamado disco protoplanetário, uma vez que se encontra na fase inicial da formação de um sistema planetário. Este disco é visto de perfil quando observado a partir da Terra e a sua aparência em imagens no visível levou a que se lhe desse o nome informal de Disco Voador.
Os astrónomos utilizaram o ALMA para observar o brilho emitido pelas moléculas de monóxido de carbono no disco da 2MASS J16281370-2431391. As imagens revelaram-se extremamente nítidas e descobriu-se algo estranho — em alguns casos o sinal recebido era negativo. Normalmente um sinal negativo é fisicamente impossível, mas neste caso existe uma explicação, que leva a uma conclusão surpreendente.
Evidence for the_thermal_sunyaev-zeldovich_effect_associated_with_quasar_feed...Sérgio Sacani
Using a radio-quiet subsample of the Sloan Digital Sky Survey spectroscopic quasar
catalogue, spanning redshifts 0.5–3.5, we derive the mean millimetre and far-infrared
quasar spectral energy distributions (SEDs) via a stacking analysis of Atacama Cosmology
Telescope and Herschel-Spectral and Photometric Imaging REceiver data. We
constrain the form of the far-infrared emission and find 3σ–4σ evidence for the thermal
Sunyaev-Zel’dovich (SZ) effect, characteristic of a hot ionized gas component with
thermal energy (6.2 ± 1.7) × 1060 erg. This amount of thermal energy is greater than
expected assuming only hot gas in virial equilibrium with the dark matter haloes of
(1 − 5) × 1012h
−1M that these systems are expected to occupy, though the highest
quasar mass estimates found in the literature could explain a large fraction of this
energy. Our measurements are consistent with quasars depositing up to (14.5±3.3) τ
−1
8
per cent of their radiative energy into their circumgalactic environment if their typical
period of quasar activity is τ8 × 108 yr. For high quasar host masses, ∼ 1013h
−1M,
this percentage will be reduced. Furthermore, the uncertainty on this percentage is
only statistical and additional systematic uncertainties enter at the 40 per cent level.
The SEDs are dust dominated in all bands and we consider various models for dust
emission. While sufficiently complex dust models can obviate the SZ effect, the SZ
interpretation remains favoured at the 3σ–4σ level for most models.
Exocometary gas in_th_hd_181327_debris_ringSérgio Sacani
An increasing number of observations have shown that gaseous debris discs are not an
exception. However, until now we only knew of cases around A stars. Here we present the first
detection of 12CO (2-1) disc emission around an F star, HD 181327, obtained with ALMA
observations at 1.3 mm. The continuum and CO emission are resolved into an axisymmetric
disc with ring-like morphology. Using a Markov chain Monte Carlo method coupled with
radiative transfer calculations we study the dust and CO mass distribution. We find the dust is
distributed in a ring with a radius of 86:0 0:4 AU and a radial width of 23:2 1:0 AU. At
this frequency the ring radius is smaller than in the optical, revealing grain size segregation
expected due to radiation pressure. We also report on the detection of low level continuum
emission beyond the main ring out to 200 AU. We model the CO emission in the non-LTE
regime and we find that the CO is co-located with the dust, with a total CO gas mass ranging
between 1:2 10 6 M and 2:9 10 6 M, depending on the gas kinetic temperature and
collisional partners densities. The CO densities and location suggest a secondary origin, i.e.
released from icy planetesimals in the ring. We derive a CO cometary composition that is
consistent with Solar system comets. Due to the low gas densities it is unlikely that the gas is
shaping the dust distribution.
We report the discovery of a new Kepler transiting circumbinary planet (CBP).
This latest addition to the still-small family of CBPs defies the current trend of known
short-period planets orbiting near the stability limit of binary stars. Unlike the previous
discoveries, the planet revolving around the eclipsing binary system Kepler-1647 has
a very long orbital period ( 1100 days) and was at conjunction only twice during
the Kepler mission lifetime. Due to the singular configuration of the system, Kepler-
1647b is not only the longest-period transiting CBP at the time of writing, but also one
of the longest-period transiting planets. With a radius of 1:060:01 RJup it is also the
largest CBP to date. The planet produced three transits in the light-curve of Kepler-
1647 (one of them during an eclipse, creating a syzygy) and measurably perturbed the
times of the stellar eclipses, allowing us to measure its mass to be 1:520:65 MJup.
The planet revolves around an 11-day period eclipsing binary consisting of two Solarmass
stars on a slightly inclined, mildly eccentric (ebin = 0:16), spin-synchronized
orbit. Despite having an orbital period three times longer than Earth’s, Kepler-1647b is
in the conservative habitable zone of the binary star throughout its orbit.
Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of
1011.5 K. Relativistic boosting can increase its observed value, but apparent brightness temperatures
much in excess of 1013 K are inaccessible using ground-based very long baseline interferometry (VLBI)
at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission
RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as
small as 26 µas (2.7 light months) and brightness temperature in excess of 1013 K. These measurements
challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive
black holes and require a much higher Doppler factor than what is determined from jet apparent
kinematics.
Keywords: galaxies: active — galaxies: jets — radio continuum: galaxies — techniques: interferometric
— quasars: individual (3C 273)
A nearby yoiung_m_dwarf_with_wide_possibly_planetary_m_ass_companionSérgio Sacani
O objeto de massa planetária J2126, anteriormente pensado como sendo um planeta solitário, orbita sua estrela mãe na maior órbita já descoberta até agora no universo, de acordo com uma equipe de astrônomos liderada pelo Dr. Niall Deacon, da Universidade de Hertfordshire, no Reino Unido.
O J2126, cujo nome completo é 2MASS J21265040-8140293, tem cerca de 13 vezes a massa de Júpiter.
Sua órbita é de aproximadamente 6900 Unidades Astronômicas de distância da sua estrela, a TYC 9486-927-1, uma estrela ativa, de rotação rápida e classificada como sendo do tipo Anã-M.
Essa é uma órbita 6900 vezes maior que a distância da Terra ao Sol, ou seja, aproximadamente 1 trilhão de quilômetros. Nessa sua órbita, o planeta leva 900000 anos para completar uma volta ao redor da sua estrela.
Supermassive black holes in galaxy centres can grow by the accretion
of gas, liberating enormous amounts of energy that might
regulate star formation on galaxy-wide scales1–3
. The nature of
gaseous fuel reservoirs that power black hole growth is nevertheless
largely unconstrained by observations, and is instead routinely
simplified as a smooth, spherical inflow of very hot gas
in accordance with the Bondi solution4
. Recent theory5–7 and
simulations8–10 instead predict that accretion can be dominated by
a stochastic, clumpy distribution of very cold molecular clouds,
though unambiguous observational support for this prediction remains
elusive. Here we show observational evidence for a cold,
clumpy accretion flow toward a supermassive black hole fuel reservoir
in the nucleus of the Abell 2597 Brightest Cluster Galaxy
(BCG), a nearby (z = 0.0821) giant elliptical galaxy surrounded
by a dense halo of hot plasma11–13. Under the right conditions,
thermal instabilities can precipitate from this hot gas, producing a
rain of cold clouds that fall toward the galaxy’s centre14, sustaining
star formation amid a kiloparsec-scale molecular nebula that inhabits
its core15. New interferometric sub-millimetre observations
show that these cold clouds also fuel black hole accretion, revealing
“shadows” cast by molecular clouds as they move inward at ∼ 300
km s−1
toward the active supermassive black hole in the galaxy
centre, which serves as a bright backlight. Corroborating evidence
from prior observations16 of warmer atomic gas at extremely high
spatial resolution17, along with simple arguments based on geometry
and probability, indicates that these clouds are within the innermost
hundred parsecs of the black hole, and falling closer toward
it
We discovered two transient events in the Kepler eld with light curves that strongly suggest they
are type II-P supernovae. Using the fast cadence of the Kepler observations we precisely estimate
the rise time to maximum for KSN2011a and KSN2011d as 10.50:4 and 13.30:4 rest-frame days
respectively. Based on ts to idealized analytic models, we nd the progenitor radius of KSN2011a
(28020 R) to be signicantly smaller than that for KSN2011d (49020 R) but both have similar
explosion energies of 2.00:3 1051 erg.
The rising light curve of KSN2011d is an excellent match to that predicted by simple models of
exploding red supergiants (RSG). However, the early rise of KSN2011a is faster than the models
predict possibly due to the supernova shockwave moving into pre-existing wind or mass-loss from the
RSG. A mass loss rate of 10 4 M yr 1 from the RSG can explain the fast rise without impacting
the optical
ux at maximum light or the shape of the post-maximum light curve.
No shock breakout emission is seen in KSN2011a, but this is likely due to the circumstellar inter-
action suspected in the fast rising light curve. The early light curve of KSN2011d does show excess
emission consistent with model predictions of a shock breakout. This is the rst optical detection of
a shock breakout from a type II-P supernova.
A 2 4_determination_of_the_local_value_of_the_hubble_constantSérgio Sacani
We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to
reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%.
The bulk of this improvement comes from new, near-infrared observations of Cepheid
variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling
the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these
in turn leverage the magnitude-redshift relation based on 300 SNe Ia at z <0.15. All
19 hosts as well as the megamaser system NGC4258 have been observed with WFC3
in the optical and near-infrared, thus nullifying cross-instrument zeropoint errors in the
relative distance estimates from Cepheids. Other noteworthy improvements include a
33% reduction in the systematic uncertainty in the maser distance to NGC4258, a larger
sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to
the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of
Cepheids in M31, and new HST-based trigonometric parallaxes for Milky Way (MW)
Cepheids.
Magnetic interaction of_a_super_cme_with_the_earths_magnetosphere_scenario_fo...Sérgio Sacani
Solar eruptions, known as Coronal Mass Ejections (CMEs), are
frequently observed on our Sun. Recent Kepler observations of super
ares
on G-type stars have implied that so called super-CMEs, possessing kinetic
energies 10 times of the most powerful CME event ever observed on the Sun,
could be produced with a frequency of 1 event per 800-2000 yr on solar-
like slowly rotating stars. We have performed a 3D time-dependent global
magnetohydrodynamic simulation of the magnetic interaction of such a CME
cloud with the Earth's magnetosphere. We calculated the global structure
of the perturbed magnetosphere and derive the latitude of the open-closed
magnetic eld boundary. We also estimated energy
uxes penetrating the
Earth's ionosphere and discuss the consequences of energetic particle
uxes
on biological systems on early Earth.
Young remmants of_type_ia_supernovae_and_their_progenitors_a_study_of_snr_g19_03Sérgio Sacani
Type Ia supernovae, with their remarkably homogeneous light curves and spectra, have been used as
standardizable candles to measure the accelerating expansion of the Universe. Yet, their progenitors
remain elusive. Common explanations invoke a degenerate star (white dwarf) which explodes upon
reaching close to the Chandrasekhar limit, by either steadily accreting mass from a companion star
or violently merging with another degenerate star. We show that circumstellar interaction in young
Galactic supernova remnants can be used to distinguish between these single and double degenerate
progenitor scenarios. Here we propose a new diagnostic, the Surface Brightness Index, which can
be computed from theory and compared with Chandra and VLA observations. We use this method
to demonstrate that a double degenerate progenitor can explain the decades-long
ux rise and size
increase of the youngest known Galactic SNR G1.9+0.3. We disfavor a single degenerate scenario.
We attribute the observed properties to the interaction between a steep ejecta prole and a constant
density environment. We suggest using the upgraded VLA to detect circumstellar interaction in
the remnants of historical Type Ia supernovae in the Local Group of galaxies. This may settle the
long-standing debate over their progenitors.
Subject headings: ISM: supernova remnants | radio continuum: general | X-rays: general | bi-
naries: general | circumstellar matter | supernovae: general | ISM: individual
objects(SNR G1.9+0.3)
Quase 900 galáxias próximas, porém escondidas, têm sido estudadas por uma equipe internacional de astrônomos, levando uma nova luz sobre o entendimento do Grande Atrator - uma concentração difusa de massa a 250 milhões de anos-luz de distância, que está puxando a nossa Via Láctea, e milhares de outras galáxias em sua direção.
Usando o Multibeam Receiver, instalado no rádio telescópio Parkes de 64 m, pertencente à instituição CSIRO na Austrália, a equipe foi capaz de ver através das estrelas e da poeira da nossa galáxia, vasculhando assim uma região inexplorada do espaço, conhecida pelos astrônomos como Zone of Avoidance (Zona de Anulação).
“Nós descobrimos 883 galáxias, um terço das quais nunca tinham sido vistas anteriormente”, disse o Professor Lister Staveley-Smith, membro da equipe, do ARC Centre of Excellence for All-sky Astrophysics, e da University of Western Australia, um dos nós do International Centre for Radio Astronomy Research.
EXTINCTION AND THE DIMMING OF KIC 8462852Sérgio Sacani
To test alternative hypotheses for the behavior of KIC 8462852, we obtained measurements of the star
over a wide wavelength range from the UV to the mid-infrared from October 2015 through December
2016, using Swift, Spitzer and at AstroLAB IRIS. The star faded in a manner similar to the longterm
fading seen in Kepler data about 1400 days previously. The dimming rate for the entire period
reported is 22.1 ± 9.7 milli-mag yr−1
in the Swift wavebands, with amounts of 21.0 ± 4.5 mmag in
the groundbased B measurements, 14.0 ± 4.5 mmag in V , and 13.0 ± 4.5 in R, and a rate of 5.0 ± 1.2
mmag yr−1 averaged over the two warm Spitzer bands. Although the dimming is small, it is seen at
& 3 σ by three different observatories operating from the UV to the IR. The presence of long-term
secular dimming means that previous SED models of the star based on photometric measurements
taken years apart may not be accurate. We find that stellar models with Tef f = 7000 - 7100 K and
AV ∼ 0.73 best fit the Swift data from UV to optical. These models also show no excess in the
near-simultaneous Spitzer photometry at 3.6 and 4.5 µm, although a longer wavelength excess from
a substantial debris disk is still possible (e.g., as around Fomalhaut). The wavelength dependence of
the fading favors a relatively neutral color (i.e., RV & 5, but not flat across all the bands) compared
with the extinction law for the general ISM (RV = 3.1), suggesting that the dimming arises from
circumstellar material
Periodic mass extinctions_and_the_planet_x_model_reconsideredSérgio Sacani
The 27 Myr periodicity in the fossil extinction record has been con-
firmed in modern data bases dating back 500 Myr, which is twice the time
interval of the original analysis from thirty years ago. The surprising regularity
of this period has been used to reject the Nemesis model. A second
model based on the sun’s vertical galactic oscillations has been challenged
on the basis of an inconsistency in period and phasing. The third astronomical
model originally proposed to explain the periodicity is the Planet
X model in which the period is associated with the perihelion precession
of the inclined orbit of a trans-Neptunian planet. Recently, and unrelated
to mass extinctions, a trans-Neptunian super-Earth planet has been proposed
to explain the observation that the inner Oort cloud objects Sedna
and 2012VP113 have perihelia that lie near the ecliptic plane. In this
Letter we reconsider the Planet X model in light of the confluence of the
modern palaeontological and outer solar system dynamical evidence.
Key Words: astrobiology - planets and satellites - Kuiper belt:
general - comets: general
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grainsSérgio Sacani
Os astrónomos usaram o ALMA e os telescópios do IRAM para fazer a primeira medição direta da temperatura dos grãos de poeira grandes situados nas regiões periféricas de um disco de formação planetária que se encontra em torno de uma estrela jovem. Ao observar de forma inovadora um objeto cujo nome informal é Disco Voador, os astrónomos descobriram que os grãos de poeira são muito mais frios do que o esperado: -266º Celsius. Este resultado surpreendente sugere que os modelos teóricos destes discos precisam de ser revistos.
Uma equipa internacional liderada por Stephane Guilloteau do Laboratoire d´Astrophysique de Bordeaux, França, mediu a temperatura de enormes grãos de poeira que se encontram em torno da jovem estrela 2MASS J16281370-2431391 na região de formação estelar Rho Ophiuchi, a cerca de 400 anos-luz de distância da Terra.
Esta estrela encontra-se rodeada por um disco de gás e poeira — chamado disco protoplanetário, uma vez que se encontra na fase inicial da formação de um sistema planetário. Este disco é visto de perfil quando observado a partir da Terra e a sua aparência em imagens no visível levou a que se lhe desse o nome informal de Disco Voador.
Os astrónomos utilizaram o ALMA para observar o brilho emitido pelas moléculas de monóxido de carbono no disco da 2MASS J16281370-2431391. As imagens revelaram-se extremamente nítidas e descobriu-se algo estranho — em alguns casos o sinal recebido era negativo. Normalmente um sinal negativo é fisicamente impossível, mas neste caso existe uma explicação, que leva a uma conclusão surpreendente.
Measurement of lmpulsive Thrust from a Closed Radio Frequency Cavity in VacuumSérgio Sacani
A vacuum test campaign evaluating the impulsive thrust performance of a tapered RF test article excited in the TM212 mode at 1,937 megahertz (MHz) has been completed. The test campaign consisted of a forward thrust phase and reverse thrust phase at less than 8 x 10-6 Torr vacuum with power scans at 40 watts, 60 watts, and 80 watts. The test campaign included a null thrust test effort to identify any mundane sources of impulsive thrust, however none were identified. Thrust data from forward, reverse, and null suggests that the system is consistently performing with a thrust to power ratio of 1.2 ± 0.1 mN/kW.
The Possible Tidal Demise of Kepler’s First Planetary SystemSérgio Sacani
We present evidence of tidally-driven inspiral in the Kepler-1658 (KOI-4) system, which consists of a giant planet
(1.1RJ, 5.9MJ) orbiting an evolved host star (2.9Re, 1.5Me). Using transit timing measurements from Kepler,
Palomar/WIRC, and TESS, we show that the orbital period of Kepler-1658b appears to be decreasing at a rate = -
+ P 131 22
20 ms yr−1
, corresponding to an infall timescale P P » 2.5 Myr. We consider other explanations for the
data including line-of-sight acceleration and orbital precession, but find them to be implausible. The observed
period derivative implies a tidal quality factor
¢ = ´ -
+ Q 2.50 10 0.62
0.85 4, in good agreement with theoretical
predictions for inertial wave dissipation in subgiant stars. Additionally, while it probably cannot explain the entire
inspiral rate, a small amount of planetary dissipation could naturally explain the deep optical eclipse observed for
the planet via enhanced thermal emission. As the first evolved system with detected inspiral, Kepler-1658 is a new
benchmark for understanding tidal physics at the end of the planetary life cycle
Confirmation of the_ogle_planet_signature_and_its_characteristics_with_lens_s...Sérgio Sacani
O Telescópio Espacial Hubble e o Observatório W. M. Keck, no Havaí, fizeram confirmações independentes de um exoplaneta orbitando sua estrela central de uma distância bem grande. O planeta foi descoberto através de uma técnica chamada de microlente gravitacional.
Essa descoberta traz uma nova peça para o processo de caçada de exoplanetas: para descobrir planetas longe de suas estrelas, como Júpiter e Saturno estão do Sol. Os resultados obtidos pelo Hubble e pelo Keck apareceram em dois artigos da edição de 30 de Julho de 2015 do The Astrophysical Journal.
A grande maioria dos exoplanetas catalogados são aqueles localizados bem perto de suas estrelas, isso acontece porque as técnicas atuais de se caçar exoplanetas favorecem a descoberta de planetas com curtos períodos orbitais. Mas esse não é o caso da técnica de microlente gravitacional, que pode encontrar planetas mais frios e mais distantes com órbitas de longo período que outros métodos não são capazes de detectar.
Direct Measure of Radiative And Dynamical Properties Of An Exoplanet AtmosphereSérgio Sacani
Two decades after the discovery of 51Pegb, the formation processes and atmospheres of short-period gas giants
remain poorly understood. Observations of eccentric systems provide key insights on those topics as they can
illuminate how a planet’s atmosphere responds to changes in incident flux. We report here the analysis of multi-day
multi-channel photometry of the eccentric (e ~ 0.93) hot Jupiter HD80606b obtained with the Spitzer Space
Telescope. The planet’s extreme eccentricity combined with the long coverage and exquisite precision of new
periastron-passage observations allow us to break the degeneracy between the radiative and dynamical timescales
of HD80606b’s atmosphere and constrain its global thermal response. Our analysis reveals that the atmospheric
layers probed heat rapidly (∼4 hr radiative timescale) from<500 to 1400 K as they absorb ~20% of the incoming
stellar flux during the periastron passage, while the planet’s rotation period is 93 35
85
-
+ hr, which exceeds the predicted
pseudo-synchronous period (40 hr).
Key words: methods: numerical – planet–star interactions – planets and satellites: atmospheres – planets and
satellites: dynamical evolution and stability – planets and satellites: individual (HD 80606 b) – techniques:
photometric
The extremely high albedo of LTT 9779 b revealed by CHEOPSSérgio Sacani
Optical secondary eclipse measurements of small planets can provide a wealth of information about the reflective properties
of these worlds, but the measurements are particularly challenging to attain because of their relatively shallow depth. If such signals
can be detected and modeled, however, they can provide planetary albedos, thermal characteristics, and information on absorbers in
the upper atmosphere.
Aims. We aim to detect and characterize the optical secondary eclipse of the planet LTT 9779 b using the CHaracterising ExOPlanet
Satellite (CHEOPS) to measure the planetary albedo and search for the signature of atmospheric condensates.
Methods. We observed ten secondary eclipses of the planet with CHEOPS. We carefully analyzed and detrended the light curves using
three independent methods to perform the final astrophysical detrending and eclipse model fitting of the individual and combined light
curves.
Results. Each of our analysis methods yielded statistically similar results, providing a robust detection of the eclipse of LTT 9779 b
with a depth of 115±24 ppm. This surprisingly large depth provides a geometric albedo for the planet of 0.80+0.10
−0.17, consistent with
estimates of radiative-convective models. This value is similar to that of Venus in our own Solar System. When combining the eclipse
from CHEOPS with the measurements from TESS and Spitzer, our global climate models indicate that LTT 9779 b likely has a super
metal-rich atmosphere, with a lower limit of 400× solar being found, and the presence of silicate clouds. The observations also reveal
hints of optical eclipse depth variability, but these have yet to be confirmed.
Conclusions. The results found here in the optical when combined with those in the near-infrared provide the first steps toward
understanding the atmospheric structure and physical processes of ultrahot Neptune worlds that inhabit the Neptune desert.
Artigo que descreve a descoberta do exoplaneta Kepler-432b, um exoplaneta mais massivo que Júpiter que orbita uma estrela gigante vermelha bem próximo e numa órbita extremamente alongada.
Confirmation of the_planetary_microlensing_signal_and_star_and_planet_mass_de...Sérgio Sacani
O Telescópio Espacial Hubble e o Observatório W. M. Keck, no Havaí, fizeram confirmações independentes de um exoplaneta orbitando sua estrela central de uma distância bem grande. O planeta foi descoberto através de uma técnica chamada de microlente gravitacional.
Essa descoberta traz uma nova peça para o processo de caçada de exoplanetas: para descobrir planetas longe de suas estrelas, como Júpiter e Saturno estão do Sol. Os resultados obtidos pelo Hubble e pelo Keck apareceram em dois artigos da edição de 30 de Julho de 2015 do The Astrophysical Journal.
A grande maioria dos exoplanetas catalogados são aqueles localizados bem perto de suas estrelas, isso acontece porque as técnicas atuais de se caçar exoplanetas favorecem a descoberta de planetas com curtos períodos orbitais. Mas esse não é o caso da técnica de microlente gravitacional, que pode encontrar planetas mais frios e mais distantes com órbitas de longo período que outros métodos não são capazes de detectar.
Eccentricity from transit_photometry_small_planets_in_kepler_multi_planet_sys...Sérgio Sacani
Artigo descreve estudo que mostra que a órbita dos exoplanetas terrestres são na sua maioria órbitas circulares, o que é bom para se procurar por vida e o que vem causando uma revolução no entendimento sobre os sistemas de exoplanteas.
A new universal formula for atoms, planets, and galaxiesIOSR Journals
In this paper a new universal formula about the rotation velocity distribution of atoms, planets, and galaxies is presented. It is based on a new general formula based on the relativistic Schwarzschild/Minkowski metric, where it has been possible to obtain expressions for the rotation velocity - and mass distribution versus the distance to the atomic nucleus, planet system centre, and galactic centre. A mathematical proof of this new formula is also given. This formula is divided into a Keplerian(general relativity)-and a relativistic(special relativity) part. For the atomic-and planet systems the Keplerian distribution is followed, which is also in accordance with observations.
According to the rotation velocity distribution of the galaxies the rotation velocity increases very rapidly from the centre and reaches a plateau which is constant out to a great distance from the centre. This is in accordance with observations and is also in accordance with the main structure of rotation velocity versus distance from different galaxy measurements.
Computer simulations were also performed to establish and verify the rotation velocity distributions in the atomic – planetary- and galaxy system, according to this paper. These computer simulations are in accordance with observations in two and three dimensions. It was also possible to study the matching percentage in these calculations showing a much higher matching percentage between theoretical and observational values by this new formula.
Uma equipe de astrofísicos usando o Observatório W. M. Keck no Havaí mediu com sucesso a galáxia mais distante já registrada e o mais interessante, capturou sua emissão de hidrogênio vista quando o universo tinha menos de 600 milhões de anos de vida. Adicionalmente, o método pelo qual a galáxia EGSY8p7 foi detectada dá uma ideia importante sobre como as primeiras estrelas no universo se acenderam depois do Big Bang.
Usando o poderoso espectrógrafo infravermelho do Observatório Keck, chamado MOSFIRE, a equipe datou a galáxia detectando sua linha de emissão Lyman-alpha – uma assinatura do gás hidrogênio quente, aquecido pela forte emissão ultravioleta de estrelas recém-nascidas. Embora, frequentemente seja possível detectar essa assinatura em galáxias próximas da Terra, a detecção da emissão Lyman-alpha nessas grandes distâncias é inesperada, já que ela é facilmente absorvida pelos numerosos átomos de hidrogênio que acredita-se existam no espaço entre as galáxias no nascer do universo. O resultado dá uma nova ideia sobre a reionização cósmica, o processo pelo qual nuvens escuras de hidrogênio foram partidas em seus prótons constituintes e elétrons pelas primeiras gerações de galáxias.
“Nós frequentemente observamos a linha de emissão Lyman-alpha do hidrogênio em objetos próximos já que eles são um dos traçadores mais confiáveis da formação de estrelas”, disse o astrônomo Adi Zitrin, do Instituto de Tecnologia da Califórnia, o Caltech, principal autor do estudo. “Contudo, à medida que penetramos mais fundo no universo, e então voltamos a tempos remotos, o espaço entre as galáxias continha um grande número de nuvens escuras de hidrogênio que absorviam esse sinal”.
WASP-69b’s Escaping Envelope Is Confined to a Tail Extending at Least 7 RpSérgio Sacani
Studying the escaping atmospheres of highly irradiated exoplanets is critical for understanding the physical
mechanisms that shape the demographics of close-in planets. A number of planetary outflows have been observed
as excess H/He absorption during/after transit. Such an outflow has been observed for WASP-69b by multiple
groups that disagree on the geometry and velocity structure of the outflow. Here, we report the detection of this
planet’s outflow using Keck/NIRSPEC for the first time. We observed the outflow 1.28 hr after egress until the
target set, demonstrating the outflow extends at least 5.8 × 105 km or 7.5 Rp This detection is significantly longer
than previous observations, which report an outflow extending ∼2.2 planet radii just 1 yr prior. The outflow is
blueshifted by −23 km s−1 in the planetary rest frame. We estimate a current mass-loss rate of 1 M⊕ Gyr−1
. Our
observations are most consistent with an outflow that is strongly sculpted by ram pressure from the stellar wind.
However, potential variability in the outflow could be due to time-varying interactions with the stellar wind or
differences in instrumental precision.
Similar to Beer analysis of_kepler_and_co_rot_light_curves_i_discovery_of_kepler_76b (20)
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Tr...Sérgio Sacani
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the
atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets
receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric
composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet
transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (Porb) of 12.76 days.
The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous Porb from TESS data. We
confirmed the transit signal and Porb using ground-based photometry with MuSCAT2 and MuSCAT3, and
validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as
well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope
and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host
star is inactive, with an X-ray-to-bolometric luminosity ratio of log 5.7 L L X bol » - . Joint analysis of the light
curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R⊕,a3σ mass upper limit of
3.9 M⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric
(TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small
list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TES...Sérgio Sacani
We report on the discovery of Gliese 12 b, the nearest transiting temperate, Earth-sized planet found to date. Gliese 12 is a
bright (V = 12.6 mag, K = 7.8 mag) metal-poor M4V star only 12.162 ± 0.005 pc away from the Solar system with one of the
lowest stellar activity levels known for M-dwarfs. A planet candidate was detected by TESS based on only 3 transits in sectors
42, 43, and 57, with an ambiguity in the orbital period due to observational gaps. We performed follow-up transit observations
with CHEOPS and ground-based photometry with MINERVA-Australis, SPECULOOS, and Purple Mountain Observatory,
as well as further TESS observations in sector 70. We statistically validate Gliese 12 b as a planet with an orbital period of
12.76144 ± 0.00006 d and a radius of 1.0 ± 0.1 R⊕, resulting in an equilibrium temperature of ∼315 K. Gliese 12 b has excellent
future prospects for precise mass measurement, which may inform how planetary internal structure is affected by the stellar
compositional environment. Gliese 12 b also represents one of the best targets to study whether Earth-like planets orbiting cool
stars can retain their atmospheres, a crucial step to advance our understanding of habitability on Earth and across the galaxy.
The importance of continents, oceans and plate tectonics for the evolution of...Sérgio Sacani
Within the uncertainties of involved astronomical and biological parameters, the Drake Equation
typically predicts that there should be many exoplanets in our galaxy hosting active, communicative
civilizations (ACCs). These optimistic calculations are however not supported by evidence, which is
often referred to as the Fermi Paradox. Here, we elaborate on this long-standing enigma by showing
the importance of planetary tectonic style for biological evolution. We summarize growing evidence
that a prolonged transition from Mesoproterozoic active single lid tectonics (1.6 to 1.0 Ga) to modern
plate tectonics occurred in the Neoproterozoic Era (1.0 to 0.541 Ga), which dramatically accelerated
emergence and evolution of complex species. We further suggest that both continents and oceans
are required for ACCs because early evolution of simple life must happen in water but late evolution
of advanced life capable of creating technology must happen on land. We resolve the Fermi Paradox
(1) by adding two additional terms to the Drake Equation: foc
(the fraction of habitable exoplanets
with significant continents and oceans) and fpt
(the fraction of habitable exoplanets with significant
continents and oceans that have had plate tectonics operating for at least 0.5 Ga); and (2) by
demonstrating that the product of foc
and fpt
is very small (< 0.00003–0.002). We propose that the lack
of evidence for ACCs reflects the scarcity of long-lived plate tectonics and/or continents and oceans on
exoplanets with primitive life.
A Giant Impact Origin for the First Subduction on EarthSérgio Sacani
Hadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. Itremains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact(MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to theaccumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, withsome of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here,we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subductioninitiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMBtemperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements inLLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications forunderstanding the diverse tectonic regimes of rocky planets.
Climate extremes likely to drive land mammal extinction during next supercont...Sérgio Sacani
Mammals have dominated Earth for approximately 55 Myr thanks to their
adaptations and resilience to warming and cooling during the Cenozoic. All
life will eventually perish in a runaway greenhouse once absorbed solar
radiation exceeds the emission of thermal radiation in several billions of
years. However, conditions rendering the Earth naturally inhospitable to
mammals may develop sooner because of long-term processes linked to
plate tectonics (short-term perturbations are not considered here). In
~250 Myr, all continents will converge to form Earth’s next supercontinent,
Pangea Ultima. A natural consequence of the creation and decay of Pangea
Ultima will be extremes in pCO2 due to changes in volcanic rifting and
outgassing. Here we show that increased pCO2, solar energy (F⨀;
approximately +2.5% W m−2 greater than today) and continentality (larger
range in temperatures away from the ocean) lead to increasing warming
hostile to mammalian life. We assess their impact on mammalian
physiological limits (dry bulb, wet bulb and Humidex heat stress indicators)
as well as a planetary habitability index. Given mammals’ continued survival,
predicted background pCO2 levels of 410–816 ppm combined with increased
F⨀ will probably lead to a climate tipping point and their mass extinction.
The results also highlight how global landmass configuration, pCO2 and F⨀
play a critical role in planetary habitability.
Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243Sérgio Sacani
The recently reported observation of VFTS 243 is the first example of a massive black-hole binary
system with negligible binary interaction following black-hole formation. The black-hole mass (≈10M⊙)
and near-circular orbit (e ≈ 0.02) of VFTS 243 suggest that the progenitor star experienced complete
collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to
constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence
level, the natal kick velocity (mass decrement) is ≲10 km=s (≲1.0M⊙), with a full probability distribution
that peaks when ≈0.3M⊙ were ejected, presumably in neutrinos, and the black hole experienced a natal
kick of 4 km=s. The neutrino-emission asymmetry is ≲4%, with best fit values of ∼0–0.2%. Such a small
neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.
Detectability of Solar Panels as a TechnosignatureSérgio Sacani
In this work, we assess the potential detectability of solar panels made of silicon on an Earth-like
exoplanet as a potential technosignature. Silicon-based photovoltaic cells have high reflectance in the
UV-VIS and in the near-IR, within the wavelength range of a space-based flagship mission concept
like the Habitable Worlds Observatory (HWO). Assuming that only solar energy is used to provide
the 2022 human energy needs with a land cover of ∼ 2.4%, and projecting the future energy demand
assuming various growth-rate scenarios, we assess the detectability with an 8 m HWO-like telescope.
Assuming the most favorable viewing orientation, and focusing on the strong absorption edge in the
ultraviolet-to-visible (0.34 − 0.52 µm), we find that several 100s of hours of observation time is needed
to reach a SNR of 5 for an Earth-like planet around a Sun-like star at 10pc, even with a solar panel
coverage of ∼ 23% land coverage of a future Earth. We discuss the necessity of concepts like Kardeshev
Type I/II civilizations and Dyson spheres, which would aim to harness vast amounts of energy. Even
with much larger populations than today, the total energy use of human civilization would be orders of
magnitude below the threshold for causing direct thermal heating or reaching the scale of a Kardashev
Type I civilization. Any extraterrrestrial civilization that likewise achieves sustainable population
levels may also find a limit on its need to expand, which suggests that a galaxy-spanning civilization
as imagined in the Fermi paradox may not exist.
Jet reorientation in central galaxies of clusters and groups: insights from V...Sérgio Sacani
Recent observations of galaxy clusters and groups with misalignments between their central AGN jets
and X-ray cavities, or with multiple misaligned cavities, have raised concerns about the jet – bubble
connection in cooling cores, and the processes responsible for jet realignment. To investigate the
frequency and causes of such misalignments, we construct a sample of 16 cool core galaxy clusters and
groups. Using VLBA radio data we measure the parsec-scale position angle of the jets, and compare
it with the position angle of the X-ray cavities detected in Chandra data. Using the overall sample
and selected subsets, we consistently find that there is a 30% – 38% chance to find a misalignment
larger than ∆Ψ = 45◦ when observing a cluster/group with a detected jet and at least one cavity. We
determine that projection may account for an apparently large ∆Ψ only in a fraction of objects (∼35%),
and given that gas dynamical disturbances (as sloshing) are found in both aligned and misaligned
systems, we exclude environmental perturbation as the main driver of cavity – jet misalignment.
Moreover, we find that large misalignments (up to ∼ 90◦
) are favored over smaller ones (45◦ ≤ ∆Ψ ≤
70◦
), and that the change in jet direction can occur on timescales between one and a few tens of Myr.
We conclude that misalignments are more likely related to actual reorientation of the jet axis, and we
discuss several engine-based mechanisms that may cause these dramatic changes.
The solar dynamo begins near the surfaceSérgio Sacani
The magnetic dynamo cycle of the Sun features a distinct pattern: a propagating
region of sunspot emergence appears around 30° latitude and vanishes near the
equator every 11 years (ref. 1). Moreover, longitudinal flows called torsional oscillations
closely shadow sunspot migration, undoubtedly sharing a common cause2. Contrary
to theories suggesting deep origins of these phenomena, helioseismology pinpoints
low-latitude torsional oscillations to the outer 5–10% of the Sun, the near-surface
shear layer3,4. Within this zone, inwardly increasing differential rotation coupled with
a poloidal magnetic field strongly implicates the magneto-rotational instability5,6,
prominent in accretion-disk theory and observed in laboratory experiments7.
Together, these two facts prompt the general question: whether the solar dynamo is
possibly a near-surface instability. Here we report strong affirmative evidence in stark
contrast to traditional models8 focusing on the deeper tachocline. Simple analytic
estimates show that the near-surface magneto-rotational instability better explains
the spatiotemporal scales of the torsional oscillations and inferred subsurface
magnetic field amplitudes9. State-of-the-art numerical simulations corroborate these
estimates and reproduce hemispherical magnetic current helicity laws10. The dynamo
resulting from a well-understood near-surface phenomenon improves prospects
for accurate predictions of full magnetic cycles and space weather, affecting the
electromagnetic infrastructure of Earth.
Extensive Pollution of Uranus and Neptune’s Atmospheres by Upsweep of Icy Mat...Sérgio Sacani
In the Nice model of solar system formation, Uranus and Neptune undergo an orbital upheaval,
sweeping through a planetesimal disk. The region of the disk from which material is accreted by
the ice giants during this phase of their evolution has not previously been identified. We perform
direct N-body orbital simulations of the four giant planets to determine the amount and origin of solid
accretion during this orbital upheaval. We find that the ice giants undergo an extreme bombardment
event, with collision rates as much as ∼3 per hour assuming km-sized planetesimals, increasing the
total planet mass by up to ∼0.35%. In all cases, the initially outermost ice giant experiences the
largest total enhancement. We determine that for some plausible planetesimal properties, the resulting
atmospheric enrichment could potentially produce sufficient latent heat to alter the planetary cooling
timescale according to existing models. Our findings suggest that substantial accretion during this
phase of planetary evolution may have been sufficient to impact the atmospheric composition and
thermal evolution of the ice giants, motivating future work on the fate of deposited solid material.
Exomoons & Exorings with the Habitable Worlds Observatory I: On the Detection...Sérgio Sacani
The highest priority recommendation of the Astro2020 Decadal Survey for space-based astronomy
was the construction of an observatory capable of characterizing habitable worlds. In this paper series
we explore the detectability of and interference from exomoons and exorings serendipitously observed
with the proposed Habitable Worlds Observatory (HWO) as it seeks to characterize exoplanets, starting
in this manuscript with Earth-Moon analog mutual events. Unlike transits, which only occur in systems
viewed near edge-on, shadow (i.e., solar eclipse) and lunar eclipse mutual events occur in almost every
star-planet-moon system. The cadence of these events can vary widely from ∼yearly to multiple events
per day, as was the case in our younger Earth-Moon system. Leveraging previous space-based (EPOXI)
lightcurves of a Moon transit and performance predictions from the LUVOIR-B concept, we derive
the detectability of Moon analogs with HWO. We determine that Earth-Moon analogs are detectable
with observation of ∼2-20 mutual events for systems within 10 pc, and larger moons should remain
detectable out to 20 pc. We explore the extent to which exomoon mutual events can mimic planet
features and weather. We find that HWO wavelength coverage in the near-IR, specifically in the 1.4 µm
water band where large moons can outshine their host planet, will aid in differentiating exomoon signals
from exoplanet variability. Finally, we predict that exomoons formed through collision processes akin
to our Moon are more likely to be detected in younger systems, where shorter orbital periods and
favorable geometry enhance the probability and frequency of mutual events.
Emergent ribozyme behaviors in oxychlorine brines indicate a unique niche for...Sérgio Sacani
Mars is a particularly attractive candidate among known astronomical objects
to potentially host life. Results from space exploration missions have provided
insights into Martian geochemistry that indicate oxychlorine species, particularly perchlorate, are ubiquitous features of the Martian geochemical landscape. Perchlorate presents potential obstacles for known forms of life due to
its toxicity. However, it can also provide potential benefits, such as producing
brines by deliquescence, like those thought to exist on present-day Mars. Here
we show perchlorate brines support folding and catalysis of functional RNAs,
while inactivating representative protein enzymes. Additionally, we show
perchlorate and other oxychlorine species enable ribozyme functions,
including homeostasis-like regulatory behavior and ribozyme-catalyzed
chlorination of organic molecules. We suggest nucleic acids are uniquely wellsuited to hypersaline Martian environments. Furthermore, Martian near- or
subsurface oxychlorine brines, and brines found in potential lifeforms, could
provide a unique niche for biomolecular evolution.
Continuum emission from within the plunging region of black hole discsSérgio Sacani
The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a
powerful probe of the mass and spin of the central black hole. The vast majority of existing ‘continuum fitting’ models neglect
emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however,
find non-zero emission sourced from these regions. In this work, we extend existing techniques by including the emission
sourced from within the plunging region, utilizing new analytical models that reproduce the properties of numerical accretion
simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component,
but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component
has been added in by hand in an ad hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum
of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional
models that neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of
intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820 + 070 black hole spin
which must be low a• < 0.5 to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission
component in the MAXI J1820 + 070 spectrum between 6 and 10 keV, highlighting the necessity of including this region. Our
continuum fitting model is made publicly available.
X-rays from a Central “Exhaust Vent” of the Galactic Center ChimneySérgio Sacani
Using deep archival observations from the Chandra X-ray Observatory, we present an analysis of
linear X-ray-emitting features located within the southern portion of the Galactic center chimney,
and oriented orthogonal to the Galactic plane, centered at coordinates l = 0.08◦
, b = −1.42◦
. The
surface brightness and hardness ratio patterns are suggestive of a cylindrical morphology which may
have been produced by a plasma outflow channel extending from the Galactic center. Our fits of the
feature’s spectra favor a complex two-component model consisting of thermal and recombining plasma
components, possibly a sign of shock compression or heating of the interstellar medium by outflowing
material. Assuming a recombining plasma scenario, we further estimate the cooling timescale of this
plasma to be on the order of a few hundred to thousands of years, leading us to speculate that a
sequence of accretion events onto the Galactic Black Hole may be a plausible quasi-continuous energy
source to sustain the observed morphology
Efficient spin-up of Earth System Models usingsequence accelerationSérgio Sacani
Marine and terrestrial biogeochemical models are key components of the Earth System Models (ESMs) used toproject future environmental changes. However, their slow adjustment time also hinders effective use of ESMsbecause of the enormous computational resources required to integrate them to a pre-industrial equilibrium. Here,a solution to this "spin-up" problem based on "sequence acceleration", is shown to accelerate equilibration of state-of-the-art marine biogeochemical models by over an order of magnitude. The technique can be applied in a "blackbox" fashion to existing models. Even under the challenging spin-up protocols used for Intergovernmental Panelon Climate Change (IPCC) simulations, this algorithm is 5 times faster. Preliminary results suggest that terrestrialmodels can be similarly accelerated, enabling a quantification of major parametric uncertainties in ESMs, improvedestimates of metrics such as climate sensitivity, and higher model resolution than currently feasible.
Enhancing Performance with Globus and the Science DMZGlobus
ESnet has led the way in helping national facilities—and many other institutions in the research community—configure Science DMZs and troubleshoot network issues to maximize data transfer performance. In this talk we will present a summary of approaches and tips for getting the most out of your network infrastructure using Globus Connect Server.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Removing Uninteresting Bytes in Software FuzzingAftab Hussain
Imagine a world where software fuzzing, the process of mutating bytes in test seeds to uncover hidden and erroneous program behaviors, becomes faster and more effective. A lot depends on the initial seeds, which can significantly dictate the trajectory of a fuzzing campaign, particularly in terms of how long it takes to uncover interesting behaviour in your code. We introduce DIAR, a technique designed to speedup fuzzing campaigns by pinpointing and eliminating those uninteresting bytes in the seeds. Picture this: instead of wasting valuable resources on meaningless mutations in large, bloated seeds, DIAR removes the unnecessary bytes, streamlining the entire process.
In this work, we equipped AFL, a popular fuzzer, with DIAR and examined two critical Linux libraries -- Libxml's xmllint, a tool for parsing xml documents, and Binutil's readelf, an essential debugging and security analysis command-line tool used to display detailed information about ELF (Executable and Linkable Format). Our preliminary results show that AFL+DIAR does not only discover new paths more quickly but also achieves higher coverage overall. This work thus showcases how starting with lean and optimized seeds can lead to faster, more comprehensive fuzzing campaigns -- and DIAR helps you find such seeds.
- These are slides of the talk given at IEEE International Conference on Software Testing Verification and Validation Workshop, ICSTW 2022.
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Le nuove frontiere dell'AI nell'RPA con UiPath Autopilot™UiPathCommunity
In questo evento online gratuito, organizzato dalla Community Italiana di UiPath, potrai esplorare le nuove funzionalità di Autopilot, il tool che integra l'Intelligenza Artificiale nei processi di sviluppo e utilizzo delle Automazioni.
📕 Vedremo insieme alcuni esempi dell'utilizzo di Autopilot in diversi tool della Suite UiPath:
Autopilot per Studio Web
Autopilot per Studio
Autopilot per Apps
Clipboard AI
GenAI applicata alla Document Understanding
👨🏫👨💻 Speakers:
Stefano Negro, UiPath MVPx3, RPA Tech Lead @ BSP Consultant
Flavio Martinelli, UiPath MVP 2023, Technical Account Manager @UiPath
Andrei Tasca, RPA Solutions Team Lead @NTT Data
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Alt. GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using ...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
SAP Sapphire 2024 - ASUG301 building better apps with SAP Fiori.pdfPeter Spielvogel
Building better applications for business users with SAP Fiori.
• What is SAP Fiori and why it matters to you
• How a better user experience drives measurable business benefits
• How to get started with SAP Fiori today
• How SAP Fiori elements accelerates application development
• How SAP Build Code includes SAP Fiori tools and other generative artificial intelligence capabilities
• How SAP Fiori paves the way for using AI in SAP apps
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
The Metaverse and AI: how can decision-makers harness the Metaverse for their...Jen Stirrup
The Metaverse is popularized in science fiction, and now it is becoming closer to being a part of our daily lives through the use of social media and shopping companies. How can businesses survive in a world where Artificial Intelligence is becoming the present as well as the future of technology, and how does the Metaverse fit into business strategy when futurist ideas are developing into reality at accelerated rates? How do we do this when our data isn't up to scratch? How can we move towards success with our data so we are set up for the Metaverse when it arrives?
How can you help your company evolve, adapt, and succeed using Artificial Intelligence and the Metaverse to stay ahead of the competition? What are the potential issues, complications, and benefits that these technologies could bring to us and our organizations? In this session, Jen Stirrup will explain how to start thinking about these technologies as an organisation.
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Pushing the limits of ePRTC: 100ns holdover for 100 daysAdtran
At WSTS 2024, Alon Stern explored the topic of parametric holdover and explained how recent research findings can be implemented in real-world PNT networks to achieve 100 nanoseconds of accuracy for up to 100 days.
1. arXiv:1304.6841v3[astro-ph.EP]10May2013
BEER analysis of Kepler and CoRoT light curves:
I. Discovery of Kepler-76b: A hot Jupiter with evidence for
superrotation
S. Faigler1
, L. Tal-Or1
, T. Mazeh1
, D. W. Latham2
and L. A. Buchhave3
ABSTRACT
We present the first case in which the BEER algorithm identified a hot Jupiter
in the Kepler light curve, and its reality was confirmed by orbital solutions based
on follow-up spectroscopy. Kepler-76b was identified by the BEER algorithm,
which detected the BEaming (sometimes called Doppler boosting) effect together
with the Ellipsoidal and Reflection/emission modulations (BEER), at an orbital
period of 1.54 days, suggesting a planetary companion orbiting the 13.3 mag
F star. Further investigation revealed that this star appeared in the Kepler
eclipsing binary catalog with estimated primary and secondary eclipse depths of
5 ×10−3
and 1 ×10−4
respectively. Spectroscopic radial-velocity follow-up obser-
vations with TRES and SOPHIE confirmed Kepler-76b as a transiting 2.0 ±0.26
MJup hot Jupiter. The mass of a transiting planet can be estimated from either
the beaming or the ellipsoidal amplitude. The ellipsoidal-based mass estimate
of Kepler-76b is consistent with the spectroscopically measured mass while the
beaming-based estimate is significantly inflated. We explain this apparent dis-
crepancy as evidence for the superrotation phenomenon, which involves eastward
displacement of the hottest atmospheric spot of a tidally-locked planet by an
equatorial super-rotating jet stream. This phenomenon was previously observed
only for HD 189733b in the infrared. We show that a phase shift of 10.3±2.0 de-
grees of the planet reflection/emission modulation, due to superrotation, explains
the apparently inflated beaming modulation, resolving the ellipsoidal/beaming
amplitude discrepancy. Kepler-76b is one of very few confirmed planets in the
Kepler light curves that show BEER modulations and the first to show superro-
tation evidence in the Kepler band. Its discovery illustrates for the first time the
ability of the BEER algorithm to detect short-period planets and brown dwarfs.
1
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv
University, Tel Aviv 69978, Israel
2
Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138
3
Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark
2. – 2 –
Subject headings: binaries: spectroscopic — methods: data analysis — planets
and satellites: detection — stars: individual (Kepler-76, KIC 4570949)
1. Introduction
CoRoT and Kepler have produced hundreds of thousands of nearly uninterrupted high
precision light curves (Auvergne et al. 2009; Koch et al. 2010) that enable detection of minute
astrophysical effects. One of these is the the beaming effect, sometimes called Doppler boost-
ing, induced by stellar radial velocity. The effect causes a decrease (increase) of the brightness
of any light source receding from (approaching) the observer (Rybicki & Lightman 1979),
on the order of 4vr/c, where vr is the radial velocity of the source, and c is the velocity
of light. Thus, periodic variation of the stellar radial velocity due to an orbiting compan-
ion produces a periodic beaming modulation of the stellar flux. Loeb & Gaudi (2003) and
Zucker, Mazeh & Alexander (2007) suggested to use this effect to identify non-eclipsing bi-
naries and exoplanets in the light curves of CoRoT and Kepler. The precision of the two
satellites is needed because even for short-period binaries, with large radial-velocity (RV)
orbital amplitudes, the beaming effect is small, on the order of 100–500 ppm (parts per
million).
As predicted, several studies identified the beaming effect in short-period known eclips-
ing binaries (van Kerkwijk et al. 2010; Rowe et al. 2011; Carter et al. 2011; Kipping & Spiegel
2011; Bloemen et al. 2011, 2012; Breton et al. 2012; Weiss et al. 2012). Yet, space missions
data can be used to identify non-eclipsing binaries through detection of the beaming effect
(Loeb & Gaudi 2003; Zucker, Mazeh & Alexander 2007). However, the beaming modulation
by itself might not be enough to identify a binary star, as periodic modulations could be
produced by other effects, stellar variability in particular (e.g., Aigrain, Favata & Gilmore
2004).
To overcome this problem, the BEER algorithm (Faigler & Mazeh 2011) searches for
stars that show in their light curves a combination of the BEaming effect with two other
effects that are produced by a short-period companion — the Ellipsoidal and the Reflection
modulations. The ellipsoidal variation (e.g., Morris 1985) is due to the tidal interaction
between the two components (see a review by Mazeh (2008)), while the reflection/heating
variation (referred to herein as the reflection modulation) is caused by the luminosity of each
component that falls on the facing half of its companion (e.g., Wilson 1990; Maxted et al.
2002; Harrison et al. 2003; For et al. 2010; Reed et al. 2010). Detecting the beaming effect
together with the ellipsoidal and reflection periodic variations, with the expected relative
amplitudes and phases, can indicate the presence of a small non-eclipsing companion. Re-
3. – 3 –
cently Faigler et al. (2012) reported RV confirmation of seven new non-eclipsing short-period
binary systems in the Kepler field, with companion minimum masses in the range 0.07–0.4
M⊙, that were discovered by the BEER algorithm.
For brown-dwarfs or planetary companions the beaming effect is even smaller, on the
order of 2–50 ppm. Interestingly, several studies were able to detect this minute effect in sys-
tems with transiting brown dwarfs and planets (Mazeh & Faigler 2010; Shporer et al. 2011;
Mazeh et al. 2012; Jackson et al. 2012; Mislis et al. 2012; Barclay et al. 2012), indicating it
may be possible to detect such non-transiting objects by identifying these effects in their
host star light curves.
This paper presents the discovery of Kepler-76b, the first hot Jupiter detected by the
BEER algorithm that was subsequently confirmed by TRES and SOPHIE RV spectroscopy.
It was identified by the BEER algorithm as a high-priority planetary candidate. Visual
inspection of its light curve revealed a V-shaped primary transit and a minute secondary
eclipse, combined with beaming, ellipsoidal, and reflection amplitudes, consistent with a
massive-planet companion. We noticed later that this star was listed in the Kepler eclips-
ing binary catalog (Prˇsa et al. 2011; Slawson et al. 2011). Based on this information spec-
troscopic follow-up observations were initiated for this target, which in turn confirmed its
planetary nature.
Section 2 presents the BEER search and the initial analysis of the Kepler light curve,
Section 3 provides the details and results of the spectroscopic observations, Section 4 de-
scribes the details and results of the light curve transits and occultations analysis, Section 5
presents the detection of evidence for superrotation in the light curve and Section 6 discusses
the implications of, and conclusions from, the findings of this paper.
2. The Photometric BEER search
To identify candidates for low-mass companions we analyzed the Kepler raw light curves
of the Q2 to Q10 quarters, spanning 831 days. We visually identified 22 time segments that
showed instrumental artifacts in the photometry, and ignored data points within those seg-
ments, removing a total of 59.9 days of data from the light curves. We also corrected
two systematic jumps at Kepler times (BJD − 2454833) of 200.32 and 246.19 days. For
each light curve, outliers were then removed by 4σ clipping and detrending was performed
using a cosine-transform filter, adapted to unevenly spaced data (Mazeh & Faigler 2010;
Mazeh et al. 2012), resulting in a cleaned and detrended light curve. We then applied
the BEER algorithm to 41,782 stars brighter than 13.7 mag, with Kepler Input Catalog
4. – 4 –
(Brown et al. 2011) radius smaller than 4R⊙, calculating the Fast Fourier Transform (FFT)
based power spectrum of the cleaned and detrended light curve of each star, interpolated
over the gaps. Next, in order to avoid spurious peaks at long periods, we divided the full
period range of each power spectrum into five sub-ranges: [0.3–1], [1–2], [2–5], [5–10], and
[10–20] days, and identified the highest peak within each sub-range. For each of the five
peaks we derived the BEER amplitudes and the estimated mass and albedo of the candidate
companion (Faigler & Mazeh 2011), assuming the peak corresponds to either the orbital pe-
riod (beaming and reflection) or half the orbital period (ellipsoidal). The BEER amplitudes
were calculated by fitting the data with the modified BEER model suggested by Mazeh et al.
(2012), that uses a Lambertian reflection/emission function.
We then selected 26 candidates with the highest signal to noise ratio for the ellipsoidal
and beaming amplitudes, and with estimated secondary mass smaller than 60 MJup and im-
plied albedo smaller than 0.5. One of these candidates was Kepler-76 (Kepler Input Catalog
number 4570949), for which visual inspection revealed primary and secondary eclipses with
depths of about 5 × 10−3
and 1 × 10−4
, respectively. This candidate was also identified as a
member of the Kepler Eclipsing Binary catalog (Prˇsa et al. 2011). Follow up spectroscopic
observations confirmed the companion as a hot Jupiter. In forthcoming papers we will report
on our observations of the 26 candidates, additional confirmation of a possible brown dwarf,
and the false-positive rate of this sample.
We report here the BEER analysis results for the light curve of Kepler-76 after mask-
ing out the transit and occultation data points. We note that in our initial detection the
BEER analysis was performed on the unmasked data, but the use a robust-fit function
(Holland & Welsch 1977) that identified the transit points as outliers resulted in similar mea-
sured BEER amplitudes. Table 1 lists for Kepler-76 the coordinates and stellar properties
from the Kepler Input Catalog (Brown et al. 2011), revised effective temperature estimate
from Pinsonneault et al. (2012), and the results of the BEER analysis. Figure 1 presents
a short section of the ‘cleaned’ (Mazeh & Faigler 2010; Faigler & Mazeh 2011) photometric
data of the host star, Figure 2 presents the FFT-based power spectrum, and Figure 3 shows
the light curve folded with the detected period. It is interesting to notice, by inspecting the
cleaned light curves (Figure 1) and the data and residuals r.m.s. (Table 1), that the effects
are significantly smaller than the light curve noise, to the point that the detected modula-
tions almost can not be recognized by eye. However, deriving the BEER photometric power
spectrum from data with time spans of hundreds of days, produces a prominent detectable
peak at the orbital period (Figure 2).
5. – 5 –
Table 1. Kepler-76: Stellar properties and BEER results
RA 19:36:46.11 Right ascension
DEC 39:37:08.4 Declination
Kp
a [mag] 13.3 Kepler band magnitude
Teff
a [K] 6196 KIC Effective temperature
Teff
b [K] 6409 ± 95 Revised effective temperature
log ga [dex] 4.388 Surface gravity
[m/H]a [dex] −0.033 Metallicity
R∗
a [R⊙] 1.12 Primary radius
M∗
c [M⊙] 1.12 Primary mass
f3
a 0.056 Average third light fraction
BEER model: With transit and occultation points masked out
Period [days] 1.5449 ± 0.0007 Orbital period
T0 − 2455000d [BJD] 737.49 ± 0.19 Orbital zero phase ephemeris
Ellipsoidal [ppm]e 21.5 ± 1.7 Ellipsoidal semi-amplitude
Beaming [ppm]e 15.6 ± 2.2 Beaming semi-amplitude
Reflection [ppm]e 56.0 ± 2.5 Lambertian reflection/emission semi-amplitude
r.m.s. cleaned data [ppm] 133 Root-mean-square of the cleaned and detrended data
r.m.s. residuals [ppm] 127 Root-mean-square of residuals of data from BEER model
afrom Kepler Input Catalog
brevised Teff from Pinsonneault et al. (2012)
ccalculated from Kepler Input Catalog log g and R
dT0 is the time in which the companion is closest to the observer, assuming a circular orbit
ecorrected for third light
6. – 6 –
765 770 775 780 785 790 795 800
−6
−5
−4
−3
−2
−1
0
1
x 10
−3
∆F/F
765 770 775 780 785 790 795 800
−5
0
5
x 10
−4
∆F/F
BJD − 2454833
Fig. 1.— The light curve of Kepler-76 for a selected time span of 37 days, after outlier
removal and long-term detrending. Top: The untruncated light curve, showing the full
depth of the transits. Bottom: The light curve with the core of the transit events truncated.
Note the different scales of the two plots. (The transit missing at time 780.9 fell in a short
gap in the raw data.)
7. – 7 –
0 0.2 0.4 0.6 0.8 1 1.2 1.4
0
10
20
30
40
50
60
70
80
Frequency [1/day]
Kepler−76 Power Spectrum
P
ν
Fig. 2.— The FFT based power spectrum of the detection. The orbital period and half-
orbital period peaks are marked by vertical dashed lines. For clarity, only the frequency
range of 0–1.5 day−1
is plotted, since no significant peak was found for frequencies higher
than 1.5 day−1
.
8. – 8 –
0 0.2 0.4 0.6 0.8 1
−1
−0.5
0
0.5
1
x 10
−4 Kepler−76
∆F/F
0 0.2 0.4 0.6 0.8 1
−5
0
5
x 10
−5
Phase
Residuals
Fig. 3.— The folded cleaned light curve binned into 100 bins. Phase zero is when the
companion is closest to the observer, while phase 0.5 is when the primary is closest to the
observer, assuming a circular orbit. The error bars represent 1σ uncertainties of the median
value of each bin, based on the scatter of data points within that bin. The line presents the
BEER model. The residuals of the data from the model are plotted in the bottom panel. For
clarity, the primary eclipse was removed. The secondary eclipse is clearly visible at phase
0.5 of the plot.
9. – 9 –
3. Spectroscopic observations
Spectroscopic observations of the candidate were obtained between 29 May and 6 Octo-
ber 2012 with the Tillinghast Reflector Echelle Spectrograph (TRES; F˝ur´esz 2008) mounted
on the 1.5-m Tillinghast Reflector at the Fred Lawrence Whipple Observatory operated by
the Smithsonian Astrophysical Observatory (SAO) on Mount Hopkins in Southern Arizona,
using the medium resolution fiber at a spectral resolution of 44,000, covering a spectral
range from 385 to 910 nm. Exposures of a Thorium-Argon hollow-cathode lamp immedi-
ately before and after each exposure were used for wavelength calibration. The spectra were
extracted and rectified to intensity vs. wavelength using standard procedures developed by
Lars Buchhave (Buchhave et al. 2010).
Additional spectroscopic observations were obtained between 17 July and 1 August 2012
with the SOPHIE spectrograph (Perruchot et al. 2008; Bouchy et al. 2009, 2013) mounted
on the 1.93-m telescope at Observatoire de Haute-Provence, France, using the High Efficiency
mode (R ∼ 39, 000 at 550 nm) of the instrument. Spectra were extracted with the online
standard pipeline.
Following a method similar to the Stellar Parameter Classification method (SPC, Buchhave et al.
2012), the atmospheric parameters of Kepler-76 were determined from the SOPHIE spec-
tra by cross-correlating the observed spectral regions not affected by telluric lines against a
library of synthetic spectra (Hauschildt et al. 1999), with varying values of effective temper-
ature Teff, surface gravity log g, metallicity [m/H] and rotational velocity v sin i. For each of
the observed spectra we derived the best set of parameters that yielded the highest correla-
tion. This was done by fitting a second degree polynomial to the maximum correlation as
function of each parameter around the synthetic spectrum that yielded the best correlation.
The final parameter values for a star were taken as the mean of the parameter values derived
for each observed spectrum of that star, weighted proportionally to the inverse of the scatter
of the maximum around the fitted polynomial.
The Phoenix library of synthetic spectra we used spans the following intervals in atmo-
spheric parameters: 3000K < Teff < 10000K, −0.5 < log g < 5.5 (cgs), and −1.5 < [m/H] <
+0.5. The spacing in Teff is 100K for Teff < 7000K, and 200K elsewhere. The spacing in
log g and [m/H] is 0.5 dex. The interval and spacing of v sin i values in our algorithm are
free parameters set by the user, since each synthetic spectrum chosen from the library is
convolved with a rotational profile G(v) (e.g., Gray (2005), p. 465; Santerne et al. (2012))
and a Gaussian representing the instrumental broadening of the lines, just before calculating
cross-correlation function.
The cross-correlation was performed using TODMOR (Zucker & Mazeh 1994; Zucker et al.
10. – 10 –
2003, 2004) — a two-dimensional correlation algorithm, assuming the light contribution of
the secondary is negligible. In TODMOR, the cross-correlation functions are calculated
separately for each echelle order, and then combined to a single cross-correlation function
according the scheme proposed by Zucker et al. (2003). The atmospheric parameters found
this way are listed in Table 2. The relatively large uncertainties result mainly from the
addition of possible systematic errors (see e.g., Bruntt et al. 2010, 2012; Torres et al. 2012).
The primary mass was estimated using the atmospheric parameters derived from the
spectra and a grid of Y2
stellar isochrones (Yi et al. 2001; Demarque et al. 2004). This
was done by taking into account all age and mass values that fall into the ellipsoid in
the (Teff, log g, [Fe/H]) space defined by the atmospheric parameters and their errors. To
illustrate the process Figure 4 shows two sets of Y2
stellar isochrones of 0.2, 0.4, 1, 2, 4, 8, and
10 Gyr — one for [Fe/H] = 0.05 (solid lines) and one for [Fe/H] = −0.27 (dashed lines).
The ellipse defined by the estimated Teff and log g and their uncertainties is also shown. A
lower limit of 0.2 Gyr on the stellar age was set to ignore possible pre-main sequence solutions.
This procedure yielded a mass estimate of 1.20 ± 0.09M⊙. Following Basu et al. (2012) we
have conservatively doubled the mass errors to take into account possible uncertainties in
stellar model parameters.
Radial velocities were derived for the TRES observations in two different ways, as de-
scribed in detail by Faigler et al. (2012). First, we derived absolute velocities using cross-
correlations of the observed spectra against the template from our library of synthetic spectra
that yielded the best match (with Teff = 6000K, log g = 4.0 cgs, v sin i = 12 km s−1
and solar
metallicity). The absolute velocity analysis used just the spectral order containing the MgIb
triplet and was calibrated using IAU RV standard stars. With the goal of achieving better
precision we also derived velocities using about two dozen spectral orders, correlating the
individual observations against a template based on the strongest exposure. Thus the multi-
order velocities are relative to the observation chosen as the template. They are reported in
Table 3.
For the SOPHIE observations, radial velocities were derived by computing the weighted
cross-correlation function (CCF) of the spectra with a numerical spectral mask of a G2V star
(Baranne et al. 1996; Pepe et al. 2002). For the last five exposures, which were contaminated
by scattered moon light, we subtracted the sky using the fiber B spectrum (Santerne et al.
2009), before deriving the radial velocities. Table 3 lists the radial-velocity measurements
and their uncertainties.
11. – 11 –
54005600580060006200640066006800
3.8
3.9
4
4.1
4.2
4.3
4.4
4.5
4.6
4.7
Teff [K]
logg[cgs]
Fig. 4.— Y2
stellar isochrones, from Demarque et al. (2004), of 0.2–10 Gyr for metallicities
[Fe/H] = 0.05 (solid lines) and [Fe/H] = −0.27 (dashed lines). The estimated Teff and log g
of Kepler-76 with their uncertainties are marked by a star and an ellipse.
Table 2: Atmospheric parameters of Kepler-76
Teff [K] 6300 ± 200
log g [dex] 4.2 ± 0.3
[m/H] [dex] −0.1 ± 0.2
v sin i [km s−1] 6.5 ± 2
M∗ [M⊙] 1.2 ± 0.2
Table 3: Radial-velocity measurements
Time [BJD−2456000] RV [km s−1
] σ [km s−1
] Instrument
76.930366 0.581 0.069 TRES
83.895818 0.161 0.110 TRES
84.868623 0.546 0.072 TRES
87.836880 0.607 0.103 TRES
107.916759 0.586 0.098 TRES
115.796005 0.727 0.114 TRES
117.775394 0.100 0.082 TRES
207.682884 0 0.069 TRES
126.378842 -4.999 0.036 SOPHIE
128.575439 -5.597 0.036 SOPHIE
129.562543 -5.081 0.056 SOPHIE
130.416149 -5.560 0.091 SOPHIE
131.389038 -5.341 0.061 SOPHIE
137.536798 -5.196 0.132 SOPHIE
138.488304 -5.194 0.057 SOPHIE
139.470933 -5.615 0.080 SOPHIE
140.470516 -4.992 0.114 SOPHIE
141.450747 -5.171 0.082 SOPHIE
12. – 12 –
The first RV measurements of Kepler-76 showed variability consistent with the pho-
tometric orbital phase, so we continued observations in order to allow an orbital solution
independent of the BEER analysis. The derived eccentricity of the solution was statistically
indistinguishable from zero, so we reran the solution with eccentricity fixed to zero. Figure 5
shows the follow-up RV measurements and the velocity curve for the orbital solution, folded
with the period found, and the top section of Table 4 lists the derived orbital elements for
the independent RV solution. The center-of-mass velocities γT and γS for the independent
RV sets from TRES and SOPHIE differ by 5.68 km s−1
. This is because the TRES velocities
are relative to the strongest observation, while the SOPHIE velocities are meant to be on
an absolute scale. If the absolute TRES velocities derived using the Mg b order are used
instead of the relative velocities, γT = −5.18 km s−1
, quite close to the SOPHIE value of
γS = −5.31 km s−1
. For the joint analysis reported below, the two independent velocity sets
were shifted to a common zeropoint using the γ velocities reported in Table 4.
Next, in order to obtain a combined solution from photometry and RV measurements, we
reran the RV model using the photometric period and ephemeris, with their uncertainties, as
priors. The bottom section of Table 4 lists the orbital elements derived from this photometry-
constrained RV solution, and the estimated minimum secondary mass, Mp sin i.
13. – 13 –
−5.8
−5.6
−5.4
−5.2
−5
−4.8
RV[km/s]
Kepler−76
0 0.2 0.4 0.6 0.8 1
−0.2
0
0.2
0.4
Phase
Res[km/s]
Fig. 5.— The RV measurements folded at the derived orbital period. In the top panel, the
solid line presents the photometry-constrained orbital RV model and the horizontal-dashed
line indicates the center-of-mass velocity. Circles denote SOPHIE RV points and squares
denote TRES RV points. The residuals are plotted at the bottom panel. Note the different
scales of the upper and lower panels.
14. – 14 –
Table 4. Orbital elements based on RV measurements
N 18 Number of RV measurements
span [days] 130.8 Time span of measurements
Independent RV solution:
T0 − 2456000 a [BJD] 126.76 ± 0.03 Orbital ephemeris
P [days] 1.5474 ± 0.0021 Orbital period
γT [km s−1] 0.365 ± 0.042 Zero point velocity of TRES
γS [km s−1] −5.315 ± 0.019 Zero point velocity of SOPHIE
KRV [km s−1] 0.308 ± 0.020 Radial velocity semi-amplitude
RV solution constrained by the
photometric period and ephemeris:
T0 − 2456000 a [BJD] 126.77 ± 0.023 Orbital ephemeris
P [days] 1.5450 ± 0.0005 Orbital period
γT [km s−1] 0.328 ± 0.032 Zero point velocity of TRES
γS [km s−1] −5.320 ± 0.020 Zero point velocity of SOPHIE
KRV [km s−1] 0.306 ± 0.020 Radial velocity semi-amplitude
Mp sin i [MJup] 1.96 ± 0.25 Minimum companion mass
a T0 is the time in which the companion is closest to the observer
15. – 15 –
4. Photometric modeling of the light curve
For a more complete photometric analysis of this transiting hot Jupiter we used the
Kepler light curves of the Q2 to Q13 quarters, spanning 1104 days. First we fitted the
cleaned and detrended data with the BEER model while masking out data points in or
around the transits and occultations. The fitted amplitudes, after correction for a third
light using the KIC estimate, are listed in Table 6. We then subtracted the BEER model
from the data and analyzed the data points in and around the transits and occultations.
For that we ran a Markov chain Monte Carlo (MCMC) analysis, while fitting the transit
data points using a long-cadence integrated Mandel & Agol (2002) model with quadratic
limb darkening, assuming a circular orbit. The model limb darkening coefficients could not
be constrained, so we kept them fixed at values interpolated from Claret & Bloemen (2011)
using the stellar parameters derived from spectroscopy. We then fitted the occultation data
keeping the geometric parameters derived from the transit fixed, and assuming a linear limb
darkening coefficient of 0.5 for the planet, while looking for the occultation depth that best
fits the data.
Figure 6 presents the cleaned and detrended data points and the best-fit Mandel & Agol
(2002) model combined with the BEER model, both folded at the orbital period. Table 5 lists
the priors and the MCMC medians and 1σ uncertainties of the posterior parameters. We note
here that the orbital period P and time of primary transit T0 listed in Table 5 were derived
from the transit data points, thus yielding high-accuracy estimates. The same parameters,
listed in Table 1, were derived from the out-of-transit data, thus yielded much lower-accuracy
estimates. The T0 values listed in both tables were not corrected for the Kepler timing error
(http://archive.stsci.edu/kepler/timing error.html), which should be taken in account when
comparing them to non-Kepler observations.
16. – 16 –
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
0.9996
0.9998
1
1.0002
1.0004
1.0006
Kepler−76: Out of transit
NormalizedFlux
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
−5
0
5
x 10
−4
Residuals
Phase
0.4 0.45 0.5 0.55 0.6
0.9996
0.9998
1
1.0002
1.0004
1.0006
Kepler−76: Occultation
NormalizedFlux
0.4 0.45 0.5 0.55 0.6
−5
0
5
x 10
−4
Residuals
Phase
−0.04 −0.02 0 0.02 0.04
0.993
0.994
0.995
0.996
0.997
0.998
0.999
1
Kepler−76: Transit
NormalizedFlux
−0.04 −0.02 0 0.02 0.04
−1
0
1
x 10
−3
Residuals
Phase
Fig. 6.— Kepler-76 cleaned and detrended data points and best-fit model, both folded at
the orbital period. In the top panel of each plot, the solid line presents the best-fit model,
and the dots present the data points. The residuals are plotted in the bottom panel. Note
the different scales of the upper and lower panel of each plot.
17. – 17 –
Table 5. Photometric light curve transit and occultation model
Parameter Median and 1σ uncertainty
Priors:
M∗ [M⊙] 1.2 ± 0.2 Primary mass
a∗ 0.313 Star linear limb darkening coefficient
b∗ 0.304 Star quadratic limb darkening coefficient
ap 0.5 Planet linear limb darkening coefficient
bp 0 Planet quadratic limb darkening coefficient
f3 0.056 Average third light fraction (From KIC)
Posteriors:
T0 [BJD] 2454966.54811 ± 0.00007 Time of primary transit
Period [days] 1.54492875 ± 0.00000027 Orbital period
i [deg] 78.0 ± 0.2 Orbital inclination
R∗/a 0.221 ± 0.003 Fractional primary radius
Rp/a 0.0214 ± 0.0008 Fractional planet radius
d2 [ppm] 98.9 ± 7.1 Occultation depth
ρ∗/ρ⊙ 0.522 ± 0.019 Primary density relative to the Sun density
R∗ [R⊙] 1.32 ± 0.08 Primary radius
Rp [RJup] 1.25 ± 0.08 Planet radius
b 0.944 ± 0.011 Impact parameter
18. – 18 –
5. Inflated beaming amplitude and planet equatorial super-rotating jet
The spectroscopic RV observations and the light curve transit and occultation analysis
yielded independent orbital solutions with ephemeris and period nicely consistent with the
BEER ephemeris and period. To compare the measured RV amplitude with the beaming-
based predicted RV amplitude, one needs to evaluate the αbeam factor, which corrects for
the Doppler shift of the stellar spectrum relative to the observed band of the telescope
(Rybicki & Lightman 1979; Faigler & Mazeh 2011).
To estimate the αbeam value, we used spectra from the library of Castelli & Kurucz
(2004) models close to the estimated temperature, metallicity and gravity of the primary
star, numerically shifting them relative to the Kepler response function, while taking into
account the photon counting nature of Kepler (Loeb & Gaudi 2003; Bloemen et al. 2011;
Faigler et al. 2012). For clarity we note that by definition αbeam = 3−α
4
= B
4
, where α is the
power-law index used by Loeb & Gaudi (2003) and B is the photon weighted bandpass-
integrated beaming factor used by Bloemen et al. (2011). The result of this calculation gave
αbeam = 0.92 ± 0.04, resulting in an RV semi-amplitude of Kbeam = 1.11 ± 0.17 km s−1
. The
RV semi-amplitude predicted from the beaming effect was 3.5 times larger than the measured
amplitude, with a difference significance of about 4.5σ between the two.
A possible explanation for this inflated photometric beaming amplitude might be a phase
shift of the reflection signal, due to the superrotation phenomenon, which involves eastward
advection of gas by an equatorial super-rotating jet within the atmosphere of a co-rotating
companion. Showman & Guillot (2002) predicted through a 3D atmospheric circulation
model that tidally-locked, short period planets develop a fast eastward, or superrotating, jet
stream that extends from the equator to latitudes of typically 20◦
− 60◦
. They showed that
in some cases (depending on the imposed stellar heating and other factors) this jet causes an
eastward displacement of the hottest regions by 10◦
−60◦
longitude from the substellar point,
resulting in a phase shift of the thermal emission phase curve of the planet. This prediction
was confirmed by Knutson et al. (2007, 2009) through Spitzer infrared observations of HD
189733, which indicated a phase shift of 16◦
± 6◦
in the 8 µm band and 20◦
− 30◦
in the
24 µm band.
In general, what we call a reflection modulation is actually the light scattered off the
planet in combination with radiation absorbed and later thermally re-emitted at different
wavelengths. The two processes are controlled by the Bond albedo, 0 < AB < 1, and the
day–night heat redistribution efficiency, 0 < ǫ < 1, which can be constrained only if observa-
tions of the phase modulation or the secondary eclipse are available in different wavelengths
(Cowan & Agol 2011). This makes it impossible to distinguish between reflected and re-
radiated photons from the single band Kepler light curve we have in hand. Cowan & Agol
19. – 19 –
(2011) discuss HAT-P-7 as an example, and show that its Kepler light curve can be explained
as mostly reflected light at one limit, to mostly thermal emission at the other limit, with an
entire range of models between them being consistent with the light curve. This is important
for the current discussion, as we expect superrotation to shift only the thermal re-emission,
while leaving the scattered light component unshifted.
To estimate the maximum fraction of the reflection amplitude originating from thermal
re-emission in our case, we follow Cowan & Agol (2011) and estimate the no albedo, no
redistribution, effective day side temperature Tǫ=0 ≈ 2670K, which translates in the Kepler
band to a maximum reflection amplitude Aref ≈ 37 ppm. This means that the measured
amplitude of ≈ 50 ppm can be explained mostly by thermal re-emission. The actual fraction
of thermal emission in this case is probably smaller, but this calculation illustrates that
the fraction of thermal emission in the visual Kepler light curve phase modulation may be
significant, making it a worthy effort to look for a superrotation phase shift in the light curve.
We suggest here, that if such a phase shift is present in the Kepler light curve, it will
show up in our phase curve model mainly as an inflated beaming amplitude. To illustrate
that we consider a simple superrotation model consisting of a phase-shifted geometric reflec-
tion/emission combined with a beaming modulation,
MSR = −Aref cos(φ + δSR) + Abeam sin φ = −Aref cos δSR cos φ + (Abeam + Aref sin δSR) sin φ ,
(1)
where Aref is the reflection/emission semi-amplitude, Abeam is the beaming semi-amplitude,
φ is the orbital phase relative to mid-transit, and δSR is the superrotation phase shift angle.
This model suggests that if a phase shift is present and the reflection amplitude is larger than,
or of the order of, the beaming amplitude, the underlined term in Eq. 1 may add substantially
to the amplitude of the sin φ modulation, mimicking an inflated beaming effect.
To test our conjecture that the beaming/ellipsoidal inconsistency is a result of a su-
perrotation phase shift of the reflection/emission phase modulation, we fitted the data
using the derived system parameters (Tables 5 and 2) and the BEER effects equations
(Faigler & Mazeh 2011), while looking for the planetary mass, geometric albedo, and phase
shift of the Lambertian phase function that minimized the χ2
of the fit. Adding the phase
shift parameter to the model resulted in a decrease of the χ2
value by 90, relative to the no-
phase-shift model, indicating a substantially better agreement of the data with a model that
combines beaming, ellipsoidal and a phase shifted Lambertian reflection. An F-test shows
that fitting the data while allowing for a phase shift, as opposed to the no-phase-shift null
model, yields a better fit with a confidence level better than 9σ. Table 6 lists the amplitudes
derived by the BEER analysis, the planetary mass derived directly from the beaming versus
the ellipsoidal amplitudes, and the spectroscopic RV derived planetary mass. The table then
20. – 20 –
lists the planetary mass, phase-shift angle and geometric albedo resulting from the superro-
tation model. The superrotation phase shift estimate is small and well within the theoretical
limit of 600
predicted by Showman & Guillot (2002). In addition, the derived planetary
mass estimate is well within the 1σ range of the RV measured planetary mass, indicating
that assuming superrotation resolves the inconsistency and provides a good estimate for the
planetary mass, derived solely from the Kepler photometry, given a good stellar model.
21. – 21 –
Table 6. BEER amplitudes, planetary mass, and superrotation phase shift angle
BEER model:
Ellipsoidal [ppm]a 21.1 ± 1.7 Ellipsoidal semi-amplitude
Beaming [ppm]a 13.5 ± 2.0 Beaming semi-amplitude
Reflection [ppm]a 50.4 ± 2.0 Reflection semi-amplitude
a2s [ppm]a −2.7 ± 1.0 sin 2φ coefficient
Mp,beam [MJup] 7.2 ± 1.4 Planetary mass derived from beaming
Mp,ellip [MJup] 2.1 ± 0.4 Planetary mass derived from ellipsoidal
Mp,RV [MJup] 2.00 ± 0.26 Planetary mass measured by spectroscopic RV
Superrotation phase-shift model solution:
Mp,SR [MJup] 2.1 ± 0.4 Planetary mass
δSR [deg] 10.3 ± 2.0 Superrotation phase shift angle
Ag 0.23 ± 0.02 Geometric albedo
N 31468 Number of data points
χ2 31465 χ2 of a model allowing for a phase shift
χ2
null 31555 χ2 of a zero phase shift model (null model)
acorrected for third light
22. – 22 –
6. Discussion
This paper presents a new hot-Jupiter companion, Kepler-76b, initially identified by
the BEER algorithm, and later confirmed by spectroscopic observations. The BEER de-
tection was based on the photometrically measured amplitudes of the BEaming, Ellipsoidal
and Reflection effects, that were consistent with a planetary companion. This is just the
third confirmed planet in the Kepler field, after HAT-P-7b (Welsh et al. 2010) and TrES-2b
(Barclay et al. 2012), that its host light curve exhibits the three phase curve effects, and is
the faintest of the three stars. It is also one of a few confirmed grazing exoplanets, showing
a V-shaped transit and a partial occultation.
We have identified an inconsistency between the beaming amplitude and the spectro-
scopically measured radial velocity. Similar inconsistencies between the planetary mass de-
rived from the beaming amplitudes and the mass derived from the ellipsoidal amplitude were
noticed previously by several authors for KOI-13 (Mazeh et al. 2012; Shporer et al. 2011) and
TrES-2 (Barclay et al. 2012). We suggest here that these inconsistencies can be explained
by a phase shift of the planetary thermal modulation due to the equatorial superrotation
phenomena predicted by Showman & Guillot (2002) and later observed by Knutson et al.
(2007, 2009) in the infrared for HD 189733. In such cases we should be able to measure the
superrotation phase-shift angle from the visual band Kepler light curve of the system. As
we do not expect scattered light to exhibit such a phase shift, visual band detection of the
superrotation phase shift may yield a constraint on the ratio of scattered light to thermally
re-emitted light from the planet.
Finally, we wish to briefly comment on the sensitivity of the BEER algorithm. The
detection presented here exhibits the lowest-mass companion identified so far by the algo-
rithm, indicating its possible current detection limit. As we require that a BEER candidate
must show statistically significant beaming and ellipsoidal effects to be considered valid,
we choose here the minimum of the semi-amplitudes of the two effects as the BEER de-
tectability parameter of a planet. To estimate our ability to detect more planets and brown
dwarfs, Figure 7 presents the calculated value of this parameter, using the Faigler & Mazeh
(2011) equations, for known exoplanets of mass higher than 0.5MJup and period shorter than
30 days, as of January 2013 (http://exoplanet.eu/), together with the measured value for
Kepler-76b. The figure shows that there are six transiting and one RV detected planets with
calculated amplitudes higher than that of Kepler-76b, suggesting that these systems could
have been detected by the BEER algorithm, if their stellar and instrumental noise were
similar to that of Kepler-76. It is also apparent that further enhancement of the algorithm
sensitivity could significantly increase the number of potentially detectable planets. Given
the fact that BEER can detect similar non-transiting objects, we expect to find more objects
23. – 23 –
once we improve our detection threshold.
24. – 24 –
10
0
10
1
10
0
10
1
min(Abeam,Aellip)[ppm]
M2
sin i [MJup
]
BEER predicted amplitudes versus planet mass
RV
Transit
Fig. 7.— The minimum of the predicted beaming and ellipsoidal semi-amplitudes, as a
function of the secondary mass, for known exoplanets of mass higher than 0.5MJup and
period shorter than 30 days. Blue dots mark exoplanets detected by RV, red circles mark
exoplanets detected by transit, and the red star marks the measured amplitude of Kepler-76b.
25. – 25 –
We are indebted to Shay Zucker for numerous helpful discussions, and to Ignasi Ribas
for discussing the thermal phase shift. We thank the referee Steven Bloemen for his valuable
remarks and suggestions, and especially for his comment about the αbeam calculation. The
research leading to these results has received funding from the European Research Council
under the EU’s Seventh Framework Programme (FP7/(2007-2013)/ ERC Grant Agreement
No. 291352). This research was supported by the ISRAEL SCIENCE FOUNDATION (grant
No. 1423/11). We feel deeply indebted to the team of the Kepler mission, that enabled us
to search and analyze their unprecedentedly accurate photometric data. All the photomet-
ric data presented in this paper were obtained from the Multimission Archive at the Space
Telescope Science Institute (MAST). STScI is operated by the Association of Universities
for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for
non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G
and by other grants and contracts. We thank the Kepler mission for partial support of the
spectroscopic observations under NASA Cooperative Agreement NNX11AB99A with the
Smithsonian Astrophysical Observatory, DWL PI. We are indebted to Andrew H. Szentgy-
orgyi, who led the TRES project, and to Gabor F˝ur´esz for his many contributions to the
success of the instrument. We thank Robert P. Stefanik, Perry Berlind, Gilbert A. Esquerdo,
and Michael L. Calkins for obtaining the TRES observations, and Allyson Bieryla and Jes-
sica Mink for help with the data analysis. This paper is based in part on observations made
at Observatoire de Haute Provence (CNRS), France. We are grateful to the OHP director
and team for the allocation of the SOPHIE observing time. We are also thankful for the
help of the night assistants, that enabled us to obtain the spectra presented here. OHP
observations were supported by the OPTICON network. OPTICON has received research
funding from the European Community’s Seventh Framework Programme.
Facilities: FLWO:1.5m(TRES) , OHP:1.93m(SOPHIE)
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This preprint was prepared with the AAS LATEX macros v5.2.