This document reports the detection of a giant planet orbiting the metal-poor star HIP 13044, which belongs to a group of stars accreted from a disrupted satellite galaxy. Radial velocity observations revealed periodic variations indicating a planetary companion with a minimum mass of 1.25 Jupiter masses and an orbital period of 16.2 days. Further analysis ruled out stellar activity as the cause, confirming the planetary origin of the radial velocity signal. As HIP 13044 likely originated from an extragalactic system, this planet may be the first discovered planet of extragalactic origin.
This document summarizes the discovery of three new planets that orbit two stars rather than a single star. Key points:
- Three planets have been discovered orbiting binary star systems using the Kepler space telescope. This confirms that circumbinary planets are common, not rare occurrences.
- Analysis estimates that at least 1% of close binary star systems have circumbinary planets, meaning there are millions distributed throughout the Milky Way.
- While these three planets are too hot or cold to support life, circumbinary planets could exist in habitable zones, though none have been found yet in such zones.
- Kepler will continue observations and may find circumbinary planets in longer orbits that could be habitable in the future.
The document summarizes information about the Mars Curiosity rover mission. It describes Curiosity's goals of investigating Martian climate, geology, and assessing habitability. It details Curiosity's landing site in Gale Crater and comparisons to previous Mars rovers. Curiosity uses a supersonic parachute during its descent through the thin Martian atmosphere to slow its descent, which involves complex fluid structure interaction challenges.
Radial velocity monitoring has found the signature of a Msin i = 1:3 M planet located within the Habitable Zone of Proxima
Centauri, the Sun’s closest neighbor (Anglada-Escudé et al. 2016). Despite a hotter past and an active host star the planet Proxima b
could have retained enough volatiles to sustain surface habitability (Ribas et al. 2016). Here we use a 3D Global Climate Model (GCM)
to simulate Proxima b’s atmosphere and water cycle for its two likely rotation modes (the 1:1 and 3:2 spin-orbit resonances) while
varying the unconstrained surface water inventory and atmospheric greenhouse eect (represented here with a CO2-N2 atmosphere.)
We find that a broad range of atmospheric compositions can allow surface liquid water. On a tidally-locked planet with a surface water
inventory larger than 0.6 Earth ocean, liquid water is always present (assuming 1 bar of N2), at least in the substellar region. Liquid
water covers the whole planet for CO2 partial pressures & 1 bar. For smaller water inventories, water can be trapped on the night side,
forming either glaciers or lakes, depending on the amount of greenhouse gases. With a non-synchronous rotation, a minimum CO2
pressure of 10 mbar (assuming 1 bar of N2) is required to avoid falling into a completely frozen snowball state if water is abundant.
If the planet is dryer, 0.5 bar of CO2 would suce to prevent the trapping of any arbitrary small water inventory into polar ice
caps. More generally, any low-obliquity planet within the classical habitable zone of its star should be in one of the climate regimes
discussed here.
We use our GCM to produce reflection/emission spectra and phase curves for the dierent rotations and surface volatile inventories.
We find that atmospheric characterization will be possible by direct imaging with forthcoming large telescopes thanks to an angular
separation of 7=D at 1 m (with the E-ELT) and a contrast of 10 7. The magnitude of the planet will allow for high-resolution
spectroscopy and the search for molecular signatures, including H2O, O2, and CO2.
The observation of thermal phase curves, although challenging, can be attempted with JWST, thanks to a contrast of 210 5 at 10 m.
Proxima b will also be an exceptional target for future IR interferometers. Within a decade it will be possible to image Proxima b and
possibly determine whether this exoplanet’s surface is habitable.
A habitable fluvio_lacustrine_at_gale_crater_mars1Sérgio Sacani
The Curiosity rover discovered fine-grained sedimentary rocks in Yellowknife Bay, Gale crater, Mars that are inferred to represent an ancient lake environment. Analysis found the environment would have been habitable by microorganisms, with a neutral pH, low salinity, and variable redox states of iron and sulfur. Key biogenic elements like carbon, hydrogen, oxygen, sulfur, nitrogen and phosphorus were detected, suggesting the environment could have supported a Martian biosphere based on chemolithoautotrophy. The habitable conditions were likely present for hundreds to tens of thousands of years. These results highlight the potential for fluvial-lacustrine environments on Mars after the Noachian period to
An earth sized_planet_in_the_habitable_zone_of_a_cool_starSérgio Sacani
This document describes the discovery of Kepler-186f, an Earth-sized planet orbiting within the habitable zone of its host star Kepler-186, a cool M-dwarf star. Kepler-186f receives a similar amount of stellar radiation as Earth and models suggest it could harbor liquid water on its surface if it has an Earth-like atmosphere. At 1.11 times the size of Earth, Kepler-186f is the smallest planet discovered to date within the habitable zone of its star. The five planets orbiting Kepler-186, including Kepler-186f, likely formed from the protoplanetary disk around the star and provide the first Earth-sized candidate for a habitable world.
The harps n-rocky_planet_search_hd219134b_transiting_rocky_planetSérgio Sacani
Usando o espectrógrafo HARPS-N acoplado ao Telescopio Nazionale Galileo no Observatório de Roque de Los Muchachos, nas Ilhas Canárias, os astrônomos descobriram três exoplanetas, classificados como Super-Terras e um gigante gasoso orbitando uma estrela próxima, chamada de HD 219134.
A HD 219134, também conhecida como HR 8832 é uma estrela do tipo anã-K de quinta magnitude, localizada a aproximadamente 21 anos-luz de distância da Terra, na constelação de Cassiopeia.
A estrela é levemente mais fria e menos massiva que o nosso sol. Ela é tão brilhante que pode ser observada a olho nu.
O sistema planetário HD 219134, abriga um planeta gigante gasoso externo e três planetas internos classificados como super-Terras, um dos quais transita em frente à estrela.
A closely packed system of low mass, low-density planets transiting kepler-11Sérgio Sacani
The document summarizes the discovery of six transiting exoplanets orbiting the star Kepler-11. Photometry from the Kepler spacecraft revealed periodic dips in the star's brightness consistent with multiple transiting planets. Six planetary candidates were identified, with orbital periods ranging from 10 to 47 days for the inner five planets. Radial velocity measurements confirmed the planetary nature of the five inner planets and allowed for mass estimates. The outermost sixth planet was also validated as a planet. Analysis of the transit times, durations and depths provided insights into the properties, dynamics, and stability of this unique six-planet system.
The kepler 10_planetary_system_revisited_by_harpsSérgio Sacani
This document discusses observations of the Kepler-10 planetary system made with the HARPS-N spectrograph. The observations resulted in improved precision for the masses of Kepler-10b and Kepler-10c. Kepler-10b's mass was determined to be 3.33 ± 0.49 Earth masses, confirming its rocky composition. Kepler-10c's mass of 17.2 ± 1.9 Earth masses makes it the first strong evidence of a class of more massive solid Neptune-sized planets with longer orbital periods. The improved mass measurements will help constrain models of the internal structure and composition of these planets.
This document summarizes the discovery of three new planets that orbit two stars rather than a single star. Key points:
- Three planets have been discovered orbiting binary star systems using the Kepler space telescope. This confirms that circumbinary planets are common, not rare occurrences.
- Analysis estimates that at least 1% of close binary star systems have circumbinary planets, meaning there are millions distributed throughout the Milky Way.
- While these three planets are too hot or cold to support life, circumbinary planets could exist in habitable zones, though none have been found yet in such zones.
- Kepler will continue observations and may find circumbinary planets in longer orbits that could be habitable in the future.
The document summarizes information about the Mars Curiosity rover mission. It describes Curiosity's goals of investigating Martian climate, geology, and assessing habitability. It details Curiosity's landing site in Gale Crater and comparisons to previous Mars rovers. Curiosity uses a supersonic parachute during its descent through the thin Martian atmosphere to slow its descent, which involves complex fluid structure interaction challenges.
Radial velocity monitoring has found the signature of a Msin i = 1:3 M planet located within the Habitable Zone of Proxima
Centauri, the Sun’s closest neighbor (Anglada-Escudé et al. 2016). Despite a hotter past and an active host star the planet Proxima b
could have retained enough volatiles to sustain surface habitability (Ribas et al. 2016). Here we use a 3D Global Climate Model (GCM)
to simulate Proxima b’s atmosphere and water cycle for its two likely rotation modes (the 1:1 and 3:2 spin-orbit resonances) while
varying the unconstrained surface water inventory and atmospheric greenhouse eect (represented here with a CO2-N2 atmosphere.)
We find that a broad range of atmospheric compositions can allow surface liquid water. On a tidally-locked planet with a surface water
inventory larger than 0.6 Earth ocean, liquid water is always present (assuming 1 bar of N2), at least in the substellar region. Liquid
water covers the whole planet for CO2 partial pressures & 1 bar. For smaller water inventories, water can be trapped on the night side,
forming either glaciers or lakes, depending on the amount of greenhouse gases. With a non-synchronous rotation, a minimum CO2
pressure of 10 mbar (assuming 1 bar of N2) is required to avoid falling into a completely frozen snowball state if water is abundant.
If the planet is dryer, 0.5 bar of CO2 would suce to prevent the trapping of any arbitrary small water inventory into polar ice
caps. More generally, any low-obliquity planet within the classical habitable zone of its star should be in one of the climate regimes
discussed here.
We use our GCM to produce reflection/emission spectra and phase curves for the dierent rotations and surface volatile inventories.
We find that atmospheric characterization will be possible by direct imaging with forthcoming large telescopes thanks to an angular
separation of 7=D at 1 m (with the E-ELT) and a contrast of 10 7. The magnitude of the planet will allow for high-resolution
spectroscopy and the search for molecular signatures, including H2O, O2, and CO2.
The observation of thermal phase curves, although challenging, can be attempted with JWST, thanks to a contrast of 210 5 at 10 m.
Proxima b will also be an exceptional target for future IR interferometers. Within a decade it will be possible to image Proxima b and
possibly determine whether this exoplanet’s surface is habitable.
A habitable fluvio_lacustrine_at_gale_crater_mars1Sérgio Sacani
The Curiosity rover discovered fine-grained sedimentary rocks in Yellowknife Bay, Gale crater, Mars that are inferred to represent an ancient lake environment. Analysis found the environment would have been habitable by microorganisms, with a neutral pH, low salinity, and variable redox states of iron and sulfur. Key biogenic elements like carbon, hydrogen, oxygen, sulfur, nitrogen and phosphorus were detected, suggesting the environment could have supported a Martian biosphere based on chemolithoautotrophy. The habitable conditions were likely present for hundreds to tens of thousands of years. These results highlight the potential for fluvial-lacustrine environments on Mars after the Noachian period to
An earth sized_planet_in_the_habitable_zone_of_a_cool_starSérgio Sacani
This document describes the discovery of Kepler-186f, an Earth-sized planet orbiting within the habitable zone of its host star Kepler-186, a cool M-dwarf star. Kepler-186f receives a similar amount of stellar radiation as Earth and models suggest it could harbor liquid water on its surface if it has an Earth-like atmosphere. At 1.11 times the size of Earth, Kepler-186f is the smallest planet discovered to date within the habitable zone of its star. The five planets orbiting Kepler-186, including Kepler-186f, likely formed from the protoplanetary disk around the star and provide the first Earth-sized candidate for a habitable world.
The harps n-rocky_planet_search_hd219134b_transiting_rocky_planetSérgio Sacani
Usando o espectrógrafo HARPS-N acoplado ao Telescopio Nazionale Galileo no Observatório de Roque de Los Muchachos, nas Ilhas Canárias, os astrônomos descobriram três exoplanetas, classificados como Super-Terras e um gigante gasoso orbitando uma estrela próxima, chamada de HD 219134.
A HD 219134, também conhecida como HR 8832 é uma estrela do tipo anã-K de quinta magnitude, localizada a aproximadamente 21 anos-luz de distância da Terra, na constelação de Cassiopeia.
A estrela é levemente mais fria e menos massiva que o nosso sol. Ela é tão brilhante que pode ser observada a olho nu.
O sistema planetário HD 219134, abriga um planeta gigante gasoso externo e três planetas internos classificados como super-Terras, um dos quais transita em frente à estrela.
A closely packed system of low mass, low-density planets transiting kepler-11Sérgio Sacani
The document summarizes the discovery of six transiting exoplanets orbiting the star Kepler-11. Photometry from the Kepler spacecraft revealed periodic dips in the star's brightness consistent with multiple transiting planets. Six planetary candidates were identified, with orbital periods ranging from 10 to 47 days for the inner five planets. Radial velocity measurements confirmed the planetary nature of the five inner planets and allowed for mass estimates. The outermost sixth planet was also validated as a planet. Analysis of the transit times, durations and depths provided insights into the properties, dynamics, and stability of this unique six-planet system.
The kepler 10_planetary_system_revisited_by_harpsSérgio Sacani
This document discusses observations of the Kepler-10 planetary system made with the HARPS-N spectrograph. The observations resulted in improved precision for the masses of Kepler-10b and Kepler-10c. Kepler-10b's mass was determined to be 3.33 ± 0.49 Earth masses, confirming its rocky composition. Kepler-10c's mass of 17.2 ± 1.9 Earth masses makes it the first strong evidence of a class of more massive solid Neptune-sized planets with longer orbital periods. The improved mass measurements will help constrain models of the internal structure and composition of these planets.
An earth mass_planet_orbiting_alpha_centauri_bSérgio Sacani
1) Astronomers have detected the smallest minimum mass planet found to date orbiting a solar-type star, Alpha Centauri B.
2) The planet has a minimum mass similar to Earth and orbits Alpha Centauri B with a period of 3.236 days, making it the closest exoplanet to our solar system discovered so far.
3) Detecting such a small planet required removing signals from stellar oscillations, granulation, magnetic activity and the binary orbit of Alpha Centauri A & B from the radial velocity measurements in order to achieve a precision of 0.8 meters/second needed to detect an Earth-sized planet.
Three new circumbinary planets have been discovered orbiting binary star systems, rather than single stars. This establishes a new class of planets and shows that circumbinary planets are not rare, with an estimated frequency of at least 1% for short-period binary systems, implying millions exist in the Milky Way. While the three discovered planets are too hot or cold to support life, circumbinary planets could potentially be habitable.
The document summarizes research on the South Pole-Aitken basin, the largest impact crater on the Moon. It is over 2,500 km in diameter and more than 12 km deep. Spacecraft data show the basin has a higher concentration of iron than surrounding lunar highlands, suggesting it may expose deeper mantle rocks. However, the exact composition is debated, with some researchers arguing mantle rocks are not present based on mineral analysis. Understanding the basin's composition could provide insights into the Moon's interior structure and composition from the impact that formed the giant crater.
This document discusses implications of new images of the Sculptured Hills unit on the Moon for understanding the relative ages of impact basins. Key points:
1) Sculptured Hills was thought to be ejecta from the Serenitatis basin, but new images show it is widespread and overlies craters postdating Serenitatis.
2) Sculptured Hills transitions into the Alpes Formation north of Mare Serenitatis, suggesting it is actually ejecta from the younger Imbrium basin.
3) If true, this implies Serenitatis is relatively old, pre-Nectarian, and that the Apollo 17 impact melts may sample the older Serenitat
This document summarizes evidence that argues against the hypothesis of a "lunar terminal cataclysm" approximately 3.9 billion years ago. It analyzes dating of lunar highland rocks and meteorites, finding they do not show a prominent peak at 3.9 billion years as expected, but rather a more uniform distribution of ages. Analysis of the cratering record of lunar basins also argues against a spike in the lunar bombardment rate at that time. Modeling of impact melt production and redistribution across the lunar surface further casts doubt on there having been a major cataclysm 3.9 billion years ago as hypothesized.
Spots and Flares, Stellar Activity with Kepler (James R. A. Davenport, 2014)James Davenport
Slides from 1-hour talk about ongoing research on stellar activity with data from NASA's Kepler space telescope. Stellar flares and starspots are the subject of investigation here.
This document summarizes the discovery of a fourth planet orbiting the red dwarf star GJ 581. The planet, called GJ 581e, has a minimum mass of 1.9 Earth masses and orbits with a period of 3.15 days, making it the innermost planet in the system. Updated radial velocity measurements also allowed the researchers to correct the orbital period of the outermost planet GJ 581d, determining it to be 66.8 days rather than the previously reported 83 days. This revised period places GJ 581d within the star's habitable zone. The researchers conclude the GJ 581 system has 4 planets, with the detection of GJ 581e being the lowest mass exoplanet
If you want to help or donate please donate at my paypal:
dyokimura@gmail.com
information about saturn
SUPPORT ME:
https://www.buymeacoffee.com/dyokimura6
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https://www.youtube.com/channel/UCoKOObshfyyxhVkw1VjyQNA
The document discusses exoplanet formation theory and detection methods. It reviews that planets likely form through core accretion, with cores forming more easily beyond the snow line. Migration may cause planets to move inward through the protoplanetary disk. Exoplanets are discovered using radial velocity, which detects planets via stellar wobble, transits, which finds planets as they pass in front of their star, and microlensing. Observations have revealed details about exoplanet compositions, atmospheres, and distributions around other stars.
The document summarizes the analysis of layered deposits inside the 174 km diameter Terby impact crater located on Mars. Stratigraphic and mineralogical analysis using multiple datasets suggests the deposits were formed subaqueously during the Noachian period. The thickest sequences display fan delta morphologies indicative of prograding/onlapping sedimentation over time. Phyllosilicates detected within layers support a sedimentary environment with sustained liquid water. Erosion during the Hesperian sculpted the current landforms, with later fluvial and then aeolian activity. Terby crater thus preserves a geologic record spanning multiple periods of Mars' history.
This document discusses galaxies and our cosmic future. It begins by describing our own Milky Way galaxy and showing images of other galaxies, including spiral and elliptical galaxies. It then discusses galaxy luminosity functions and observations made using large telescopes. The document concludes by noting it was presented by Charles Liu at the American Museum of Natural History on September 23, 2011 and was about galaxies and our cosmic future.
Curiosity at gale_crater_characterization_and_analysis_of_the_rocknest_sand_s...Sérgio Sacani
The Rocknest sand shadow analyzed by the Curiosity rover on Mars was similar to coarse-grained ripples analyzed by previous rovers. It consisted of an upper layer of very coarse sand grains armoring the surface, underlain by finer grains. Analysis found the sand was around 55% crystalline material of basaltic composition and 45% amorphous iron-rich glass. This amorphous component contained the volatiles detected and was similar to soils analyzed at other Mars sites, implying the materials were locally derived from similar basaltic sources globally on Mars.
Jupiter is the largest planet in our Solar System. Several spacecraft have observed Jupiter up close, including Pioneer 10 and 11, Voyager 1 and 2, Ulysses, Galileo, Hubble Space Telescope and Cassini. These observations have revealed that Jupiter has a dynamic atmosphere with colorful cloud bands and massive storms like the Great Red Spot. The atmosphere also experiences lightning and auroras near its poles due to Jupiter's strong magnetic field. Beneath the clouds, Jupiter is likely composed primarily of liquid metallic hydrogen.
Olivine in an_unexpected_location_on_vesta_surfaceSérgio Sacani
The document reports on the discovery of olivine on the surface of the asteroid Vesta in unexpected locations, based on data from the Dawn spacecraft's VIR instrument. Specifically:
- Olivine was found in the northern hemisphere of Vesta, rather than the southern basins where mantle rocks were expected based on previous models.
- The olivine occurs in large patches hundreds of meters across mixed with howardite regolith, unlike in meteorites where it is a minor component of diogenites.
- The amount and distribution of olivine-rich material suggests a complex evolutionary history for Vesta and is not consistent with previous ideas of olivine occurrence being associated with diogenites
This document summarizes the discovery of a transiting circumbinary planet (PH1) in a quadruple star system by volunteers with the Planet Hunters citizen science project. PH1 orbits outside a 20-day eclipsing binary consisting of an F dwarf and an M dwarf star. It has a radius of 6.18 ± 0.17 R⊕ and an upper mass limit of 169 M⊕. Beyond PH1's orbit is a distant visual binary bound to the system, making this the first known case of a transiting planet in a quadruple star configuration. Planet Hunters volunteers identified transit features in the Kepler light curve of KIC 4862625 through visual inspection and discussion, leading to the confirmation and characterization
1) Global climate models that include sophisticated cloud schemes show that tidally locked planets can develop thick water clouds near the substellar point due to strong convection. These clouds greatly increase the planetary albedo and stabilize temperatures, allowing habitability at twice the stellar flux previously thought possible.
2) The cloud feedback is stabilizing, as higher stellar flux produces stronger convection and higher albedos. Substellar clouds can block outgoing radiation, reducing the day-night temperature contrast.
3) Non-tidally locked planets do not experience this stabilizing cloud feedback, as clouds only form over parts of the tropics and mid-latitudes. Their albedo decreases with increasing stellar flux, producing a destabil
1. This document discusses exoplanets and the possibility of life existing on them.
2. It provides information on the transit method used to detect exoplanets and describes how astronomers analyzed data from 3 stars, one with a confirmed exoplanet, to detect changes in brightness indicating a planet.
3. Specific exoplanets thought to potentially support life are mentioned, including Gliese 581 d which is suggested to have conditions making life possible due to possessing water, an atmosphere, and temperatures within the habitable range.
New Horizon: The First Mission to the Pluto System and the Kuiper BeltSOCIEDAD JULIO GARAVITO
The New Horizons mission aims to explore Pluto and the Kuiper Belt, sending a spacecraft on a long journey to answer questions about these distant bodies. The spacecraft launched in 2006 and will conduct the first reconnaissance of Pluto with a closest approach in July 2015. It will then head deeper into the Kuiper Belt to examine ancient icy mini-worlds over a billion miles past Neptune's orbit. Studying Pluto and Kuiper Belt objects will help scientists understand where they fit in the solar system and how icy dwarf planets have evolved over time.
This document discusses exoplanets and the search for extraterrestrial life. It describes how over 1800 exoplanets have been discovered orbiting stars other than the sun. It explains several methods used to detect exoplanets, including direct imaging, the transit method, astrometry, and radial velocity. It also discusses characteristics of potentially habitable exoplanets and provides details about Gliese 667 Cc, one of the most Earth-like exoplanets discovered. The document then reviews the history of exoplanet detection and outlines some of the earliest projects in the search for extraterrestrial intelligence, such as Projects Ozma and Phoenix.
New Horizons was NASA's first mission to Pluto and the Kuiper Belt. It conducted a flyby of Pluto on July 14, 2015, returning high-resolution images and data of the dwarf planet and its moons. New Horizons is continuing its journey deeper into the Kuiper Belt to study more Kuiper Belt Objects using its suite of scientific instruments. The mission aims to help scientists better understand the formation and evolution of the outer solar system.
The exceptional soft_x_ray_halo_of_the_galaxy_merger_ngc6240Sérgio Sacani
The document summarizes a recent 150-ks Chandra observation of the galaxy merger NGC 6240. Extended soft X-ray emission is detected over a 110x80 kpc region around NGC 6240. Spectral analysis finds the emission comes from hot gas with a temperature of around 7.5 million K and a total mass of about 10^10 solar masses. The gas properties suggest widespread star formation over the past 200 Myr rather than a recent nuclear starburst. The fate of the diffuse hot gas after the galaxy merger is uncertain but it may be retained and evolve into the halo of an elliptical galaxy.
3C 273 was one of the first quasars discovered in 1963. It remains one of the brightest and best studied quasars. It is located approximately 3 billion light years from Earth and radiates energy equivalent to 1014 times the luminosity of the Sun. 3C 273 plays a key role in understanding the nature of quasars as powered by accretion disks around supermassive black holes. It continues to be intensely observed across the electromagnetic spectrum to better understand the physics occurring in these energetic and distant cosmic objects.
An earth mass_planet_orbiting_alpha_centauri_bSérgio Sacani
1) Astronomers have detected the smallest minimum mass planet found to date orbiting a solar-type star, Alpha Centauri B.
2) The planet has a minimum mass similar to Earth and orbits Alpha Centauri B with a period of 3.236 days, making it the closest exoplanet to our solar system discovered so far.
3) Detecting such a small planet required removing signals from stellar oscillations, granulation, magnetic activity and the binary orbit of Alpha Centauri A & B from the radial velocity measurements in order to achieve a precision of 0.8 meters/second needed to detect an Earth-sized planet.
Three new circumbinary planets have been discovered orbiting binary star systems, rather than single stars. This establishes a new class of planets and shows that circumbinary planets are not rare, with an estimated frequency of at least 1% for short-period binary systems, implying millions exist in the Milky Way. While the three discovered planets are too hot or cold to support life, circumbinary planets could potentially be habitable.
The document summarizes research on the South Pole-Aitken basin, the largest impact crater on the Moon. It is over 2,500 km in diameter and more than 12 km deep. Spacecraft data show the basin has a higher concentration of iron than surrounding lunar highlands, suggesting it may expose deeper mantle rocks. However, the exact composition is debated, with some researchers arguing mantle rocks are not present based on mineral analysis. Understanding the basin's composition could provide insights into the Moon's interior structure and composition from the impact that formed the giant crater.
This document discusses implications of new images of the Sculptured Hills unit on the Moon for understanding the relative ages of impact basins. Key points:
1) Sculptured Hills was thought to be ejecta from the Serenitatis basin, but new images show it is widespread and overlies craters postdating Serenitatis.
2) Sculptured Hills transitions into the Alpes Formation north of Mare Serenitatis, suggesting it is actually ejecta from the younger Imbrium basin.
3) If true, this implies Serenitatis is relatively old, pre-Nectarian, and that the Apollo 17 impact melts may sample the older Serenitat
This document summarizes evidence that argues against the hypothesis of a "lunar terminal cataclysm" approximately 3.9 billion years ago. It analyzes dating of lunar highland rocks and meteorites, finding they do not show a prominent peak at 3.9 billion years as expected, but rather a more uniform distribution of ages. Analysis of the cratering record of lunar basins also argues against a spike in the lunar bombardment rate at that time. Modeling of impact melt production and redistribution across the lunar surface further casts doubt on there having been a major cataclysm 3.9 billion years ago as hypothesized.
Spots and Flares, Stellar Activity with Kepler (James R. A. Davenport, 2014)James Davenport
Slides from 1-hour talk about ongoing research on stellar activity with data from NASA's Kepler space telescope. Stellar flares and starspots are the subject of investigation here.
This document summarizes the discovery of a fourth planet orbiting the red dwarf star GJ 581. The planet, called GJ 581e, has a minimum mass of 1.9 Earth masses and orbits with a period of 3.15 days, making it the innermost planet in the system. Updated radial velocity measurements also allowed the researchers to correct the orbital period of the outermost planet GJ 581d, determining it to be 66.8 days rather than the previously reported 83 days. This revised period places GJ 581d within the star's habitable zone. The researchers conclude the GJ 581 system has 4 planets, with the detection of GJ 581e being the lowest mass exoplanet
If you want to help or donate please donate at my paypal:
dyokimura@gmail.com
information about saturn
SUPPORT ME:
https://www.buymeacoffee.com/dyokimura6
CHECK MY GAMING CHANNEL:
https://www.youtube.com/channel/UCoKOObshfyyxhVkw1VjyQNA
The document discusses exoplanet formation theory and detection methods. It reviews that planets likely form through core accretion, with cores forming more easily beyond the snow line. Migration may cause planets to move inward through the protoplanetary disk. Exoplanets are discovered using radial velocity, which detects planets via stellar wobble, transits, which finds planets as they pass in front of their star, and microlensing. Observations have revealed details about exoplanet compositions, atmospheres, and distributions around other stars.
The document summarizes the analysis of layered deposits inside the 174 km diameter Terby impact crater located on Mars. Stratigraphic and mineralogical analysis using multiple datasets suggests the deposits were formed subaqueously during the Noachian period. The thickest sequences display fan delta morphologies indicative of prograding/onlapping sedimentation over time. Phyllosilicates detected within layers support a sedimentary environment with sustained liquid water. Erosion during the Hesperian sculpted the current landforms, with later fluvial and then aeolian activity. Terby crater thus preserves a geologic record spanning multiple periods of Mars' history.
This document discusses galaxies and our cosmic future. It begins by describing our own Milky Way galaxy and showing images of other galaxies, including spiral and elliptical galaxies. It then discusses galaxy luminosity functions and observations made using large telescopes. The document concludes by noting it was presented by Charles Liu at the American Museum of Natural History on September 23, 2011 and was about galaxies and our cosmic future.
Curiosity at gale_crater_characterization_and_analysis_of_the_rocknest_sand_s...Sérgio Sacani
The Rocknest sand shadow analyzed by the Curiosity rover on Mars was similar to coarse-grained ripples analyzed by previous rovers. It consisted of an upper layer of very coarse sand grains armoring the surface, underlain by finer grains. Analysis found the sand was around 55% crystalline material of basaltic composition and 45% amorphous iron-rich glass. This amorphous component contained the volatiles detected and was similar to soils analyzed at other Mars sites, implying the materials were locally derived from similar basaltic sources globally on Mars.
Jupiter is the largest planet in our Solar System. Several spacecraft have observed Jupiter up close, including Pioneer 10 and 11, Voyager 1 and 2, Ulysses, Galileo, Hubble Space Telescope and Cassini. These observations have revealed that Jupiter has a dynamic atmosphere with colorful cloud bands and massive storms like the Great Red Spot. The atmosphere also experiences lightning and auroras near its poles due to Jupiter's strong magnetic field. Beneath the clouds, Jupiter is likely composed primarily of liquid metallic hydrogen.
Olivine in an_unexpected_location_on_vesta_surfaceSérgio Sacani
The document reports on the discovery of olivine on the surface of the asteroid Vesta in unexpected locations, based on data from the Dawn spacecraft's VIR instrument. Specifically:
- Olivine was found in the northern hemisphere of Vesta, rather than the southern basins where mantle rocks were expected based on previous models.
- The olivine occurs in large patches hundreds of meters across mixed with howardite regolith, unlike in meteorites where it is a minor component of diogenites.
- The amount and distribution of olivine-rich material suggests a complex evolutionary history for Vesta and is not consistent with previous ideas of olivine occurrence being associated with diogenites
This document summarizes the discovery of a transiting circumbinary planet (PH1) in a quadruple star system by volunteers with the Planet Hunters citizen science project. PH1 orbits outside a 20-day eclipsing binary consisting of an F dwarf and an M dwarf star. It has a radius of 6.18 ± 0.17 R⊕ and an upper mass limit of 169 M⊕. Beyond PH1's orbit is a distant visual binary bound to the system, making this the first known case of a transiting planet in a quadruple star configuration. Planet Hunters volunteers identified transit features in the Kepler light curve of KIC 4862625 through visual inspection and discussion, leading to the confirmation and characterization
1) Global climate models that include sophisticated cloud schemes show that tidally locked planets can develop thick water clouds near the substellar point due to strong convection. These clouds greatly increase the planetary albedo and stabilize temperatures, allowing habitability at twice the stellar flux previously thought possible.
2) The cloud feedback is stabilizing, as higher stellar flux produces stronger convection and higher albedos. Substellar clouds can block outgoing radiation, reducing the day-night temperature contrast.
3) Non-tidally locked planets do not experience this stabilizing cloud feedback, as clouds only form over parts of the tropics and mid-latitudes. Their albedo decreases with increasing stellar flux, producing a destabil
1. This document discusses exoplanets and the possibility of life existing on them.
2. It provides information on the transit method used to detect exoplanets and describes how astronomers analyzed data from 3 stars, one with a confirmed exoplanet, to detect changes in brightness indicating a planet.
3. Specific exoplanets thought to potentially support life are mentioned, including Gliese 581 d which is suggested to have conditions making life possible due to possessing water, an atmosphere, and temperatures within the habitable range.
New Horizon: The First Mission to the Pluto System and the Kuiper BeltSOCIEDAD JULIO GARAVITO
The New Horizons mission aims to explore Pluto and the Kuiper Belt, sending a spacecraft on a long journey to answer questions about these distant bodies. The spacecraft launched in 2006 and will conduct the first reconnaissance of Pluto with a closest approach in July 2015. It will then head deeper into the Kuiper Belt to examine ancient icy mini-worlds over a billion miles past Neptune's orbit. Studying Pluto and Kuiper Belt objects will help scientists understand where they fit in the solar system and how icy dwarf planets have evolved over time.
This document discusses exoplanets and the search for extraterrestrial life. It describes how over 1800 exoplanets have been discovered orbiting stars other than the sun. It explains several methods used to detect exoplanets, including direct imaging, the transit method, astrometry, and radial velocity. It also discusses characteristics of potentially habitable exoplanets and provides details about Gliese 667 Cc, one of the most Earth-like exoplanets discovered. The document then reviews the history of exoplanet detection and outlines some of the earliest projects in the search for extraterrestrial intelligence, such as Projects Ozma and Phoenix.
New Horizons was NASA's first mission to Pluto and the Kuiper Belt. It conducted a flyby of Pluto on July 14, 2015, returning high-resolution images and data of the dwarf planet and its moons. New Horizons is continuing its journey deeper into the Kuiper Belt to study more Kuiper Belt Objects using its suite of scientific instruments. The mission aims to help scientists better understand the formation and evolution of the outer solar system.
The exceptional soft_x_ray_halo_of_the_galaxy_merger_ngc6240Sérgio Sacani
The document summarizes a recent 150-ks Chandra observation of the galaxy merger NGC 6240. Extended soft X-ray emission is detected over a 110x80 kpc region around NGC 6240. Spectral analysis finds the emission comes from hot gas with a temperature of around 7.5 million K and a total mass of about 10^10 solar masses. The gas properties suggest widespread star formation over the past 200 Myr rather than a recent nuclear starburst. The fate of the diffuse hot gas after the galaxy merger is uncertain but it may be retained and evolve into the halo of an elliptical galaxy.
3C 273 was one of the first quasars discovered in 1963. It remains one of the brightest and best studied quasars. It is located approximately 3 billion light years from Earth and radiates energy equivalent to 1014 times the luminosity of the Sun. 3C 273 plays a key role in understanding the nature of quasars as powered by accretion disks around supermassive black holes. It continues to be intensely observed across the electromagnetic spectrum to better understand the physics occurring in these energetic and distant cosmic objects.
One armed spiral_waves_in_galaxy_simulations_with_computer_rotating_starsSérgio Sacani
This document summarizes simulations of disk galaxies with counter-rotating stars. The simulations found:
1) The formation of stationary one-armed spiral waves in galaxies with 25%, 37.5%, and 50% of stars counter-rotating.
2) These one-armed spirals persisted from a few to five rotation periods.
3) In some cases, the spiral wave changed direction over one rotation period, transforming from a leading to trailing arm.
The results support the theory that counter-rotating stars can drive a two-stream instability that forms one-armed spiral waves via gravitational interactions between the co- and counter-rotating populations.
Herschel far infrared_spectroscopy_of_the_galactic_centerSérgio Sacani
The document summarizes observations from the Herschel Space Observatory of the Galactic Center region, focusing on a spectral scan toward Sagittarius A*. Key findings include:
1) Strong emission from atomic fine structure lines and rotationally excited lines of molecules like CO, H2O and HCO+ are detected.
2) The excitation of the CO ladder is consistent with either a hot isothermal gas component at 103.1 K and 104 cm-3, or a distribution of warmer gas at higher densities, with most CO at 300 K.
3) The detected molecular features suggest heating is from a combination of UV irradiation and shocks in the gas, rather than very enhanced X-ray or cosmic
Hd140283 a star_in_the_solar_neighborhood_that_formed_shortly_after_the_big_bangSérgio Sacani
This document summarizes a study that measured the parallax of the star HD 140283 using the Hubble Space Telescope's Fine Guidance Sensors. The study found a parallax of 17.15 ± 0.14 mas, improving on the previous measurement from Hipparcos. Using modern stellar evolution models, the authors estimate an age for HD 140283 of 14.46 ± 0.31 Gyr based on its precise distance, making it one of the oldest stars known. While its age is consistent with the age of the Universe, uncertainties in the star's composition increase the total age uncertainty to about ±0.8 Gyr. HD 140283 likely formed shortly after the Big Bang.
This document provides an overview of the STS-134 mission including objectives, crew, payloads, experiments, and timeline. The mission will deliver supplies and experiments to the International Space Station using the space shuttle Endeavour. Key objectives include delivering the Alpha Magnetic Spectrometer and Express Logistics Carrier to the ISS and conducting three spacewalks. The crew will return research samples and conduct several short-term experiments over a 16 day mission before landing back on Earth.
Titan obliquity as evidence for a subsurface oceanSérgio Sacani
This document summarizes a study investigating whether Titan's obliquity provides evidence for a subsurface ocean. The study finds that Titan's observed obliquity of 0.3° is inconsistent with its estimated moment of inertia if Titan is entirely solid. However, the study develops a new Cassini state model that assumes Titan has a liquid water ocean beneath an ice shell. This model considers gravitational and pressure torques between layers. With this model, the study finds better agreement between Titan's moment of inertia and rotation state than for the solid case, strengthening the possibility that Titan has a subsurface ocean.
Herschel galactic plane_survey_the_global_distribution_of_ism_gas_componnentSérgio Sacani
This document summarizes a study using Herschel observations of the [C ii] 158μm line to analyze the distribution of different gas components in the Milky Way galaxy. The observations provide high-resolution maps of [C ii] emission across the Galactic plane. By comparing these maps to observations of HI, CO, and other tracers, the study finds that [C ii] emission is associated with spiral arms between 4-10 kpc from the Galactic center. It estimates that [C ii] traces dense photon-dominated regions (47%), CO-dark H2 gas (28%), cold atomic gas (21%), and ionized gas (4%). The study also analyzes the distribution of cold neutral medium versus
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that some parts of the lunar interior contain as much water as Earth's upper mantle. The similarities to Earth and differences from previous models have implications for understanding the formation of the Earth-Moon system and the presence of water on the Moon.
This document summarizes observations of the debris disk around the subgiant star κ CrB using Herschel and Keck. Herschel spatially resolved images of the debris disk, the first such images of a disk around a subgiant star. Keck radial velocity monitoring provided evidence for a second planetary companion around κ CrB. Keck adaptive optics imaging placed an upper limit on the mass of this companion. Modeling of the Herschel images showed the dust is broadly distributed but could not distinguish between a single wide belt or two narrow belts. The observations are consistent with dynamical depletion or collisional erosion clearing the inner regions of the disk.
Architecture and dynamics of kepler's candidate multiple transiting planet sy...Sérgio Sacani
This document summarizes the architecture and dynamics of Kepler's candidate multiple transiting planet systems. It finds:
1) Virtually all systems are dynamically stable based on numerical integration assuming a mass-radius relationship.
2) The distribution of observed period ratios is clustered just outside resonances, particularly the 2:1 resonance.
3) These characteristics suggest the majority of multi-candidate systems are true planetary systems, not false positives.
Characteristics of planetary candidates observed by kepler, ii analysis of t...Sérgio Sacani
This document summarizes the analysis of the first four months of data from the Kepler Mission, which observed 156,453 stars between May and September 2009. A total of 1235 planetary candidates were detected orbiting 997 host stars. The candidates range in size from Earth-sized (68 candidates) to larger than Jupiter (19 candidates). 54 candidates were found in the habitable zone, with 5 being less than twice Earth's size. Over 74% of candidates are smaller than Neptune. The number of candidates peaks at 2-3 times Earth's size and then declines with increasing size. After correcting for biases, the estimated frequency of planets is 6% for Earth-sized, 7% for super-Earth sized, 17%
This document summarizes the analysis of periodic variable stars in the open cluster NGC 3766 based on a 7-year monitoring campaign. The authors detected a new class of 36 variable stars located between the instability strips for slowly pulsating B stars and delta Scuti stars, where no variability was previously predicted. The majority of these new variables have periods between 0.1-0.7 days and amplitudes of 1-4 millimagnitudes. The properties of this new class are discussed and the authors argue they are likely pulsating variables sustained by stellar rotation. Additionally, the authors identify other periodic variables such as eclipsing binaries, slowly pulsating B stars, delta Scuti stars, and gamma Doradus candidates.
A population of_fast_radio_bursts_ar_cosmological_distancesSérgio Sacani
1) Four fast radio bursts (FRBs) lasting only a few milliseconds were detected in a radio survey of the high Galactic latitude sky.
2) The bursts' properties indicate they are of celestial rather than terrestrial origin and likely originate from cosmological distances of 0.5 to 3 billion light years.
3) No coincident x-ray or gamma-ray signals were found associated with the bursts. Characterizing the population of FRBs could help determine the baryonic content of the universe.
Imprints of fast rotating massive stars in the galactic bulgeSérgio Sacani
This document summarizes the analysis of spectra from 8 stars in the oldest globular cluster in the Galaxy, NGC 6522. The analysis reveals unusually high abundances of the heavy elements barium (Ba) and lanthanum (La), which are produced through the slow neutron capture process (s-process) in low-mass stars. However, the stars also show overabundances of the light elements yttrium (Y) and strontium (Sr) compared to iron, with a large scatter similar to that seen in extremely metal-poor stars. This pattern is best explained by enrichment from fast-rotating massive metal-poor stars, which models show can boost s-process yields through rotational mixing. The study suggests
This document appears to be citing the same source multiple times without providing any additional context or information. It repeats "1987MNRAS.227..361M" over a dozen times but does not explain the content or significance of the source being cited.
Dissecting x ray_emitting_gas_around_the_center_of_our_galaxySérgio Sacani
1) The Chandra X-ray Observatory was used to observe the supermassive black hole at the center of the Milky Way, Sgr A*, for a total of 3 megaseconds.
2) The observations revealed extended X-ray emission around Sgr A* that aligns spatially with a surrounding disk of massive stars.
3) Spectral analysis ruled out low-mass stars as the origin of the X-ray emission and instead found evidence that the emission is from a radiatively inefficient accretion flow onto the black hole, with an outflow present.
Lunar ejecta origin of near-Earth asteroid Kamo’oalewa is compatible with rar...Sérgio Sacani
Near-Earth asteroid, Kamo’oalewa (469219), is one of a small number of known quasisatellites of Earth; it transitions between quasi-satellite and horseshoe orbital states on
centennial timescales, maintaining this dynamics over megayears. The similarity of its
reflectance spectrum to lunar silicates and its Earth-like orbit both suggest that it originated
from the lunar surface. Here we carry out numerical simulations of the dynamical evolution of
particles launched from different locations on the lunar surface with a range of ejection
velocities in order to assess the hypothesis that Kamo‘oalewa originated as a debris-fragment
from a meteoroidal impact with the lunar surface. As these ejecta escape the Earth-Moon
environment, they face a dynamical barrier for entry into Earth’s co-orbital space. However, a
small fraction of launch conditions yields outcomes that are compatible with Kamo‘oalewa’s
orbit. The most favored conditions are launch velocities slightly above the escape velocity
from the trailing lunar hemisphere.
Telescópio Espacial Kepler descobre primeiro exoplaneta do tamanho da Terra n...GOASA
This document describes the discovery of Kepler-186f, an Earth-sized planet orbiting within the habitable zone of its host star Kepler-186, a cool M-dwarf star. Kepler-186f receives a similar amount of stellar radiation as Earth and models suggest it could harbor liquid water on its surface if it has an Earth-like atmosphere. At 1.11 times the size of Earth, it is the smallest planet discovered to date within the habitable zone of its star. The five planets orbiting Kepler-186, including Kepler-186f, likely formed from the protoplanetary disk around the star and may have migrated inward over time. Kepler-186f's orbit places it in a region where
No xrays from_wasp18_implications_for_its_age_activity_and_influenceSérgio Sacani
1) An 87 ks Chandra observation was performed of the star WASP-18, which hosts a very close-in hot Jupiter planet orbiting within 20 hours.
2) WASP-18 was not detected in X-rays down to a luminosity limit of 4 x 10^26 erg/s, over two orders of magnitude lower than expected for a star of its estimated age of 600 Myr.
3) This unusually low activity level for a star of WASP-18's age and mass suggests that the massive planet may play a role in disrupting the stellar magnetic dynamo generated within its thin convective layers through star-planet interaction.
WASP-18: NASA's Chandra X-ray Observatory Finds Planet That Makes Star Act De...GOASA
This document summarizes a study observing the star WASP-18 and its hot Jupiter planet using the Chandra X-ray Observatory. The star was not detected in X-rays down to a luminosity limit much lower than expected for its estimated age of 600 million years. This suggests unusual lack of magnetic activity, which the authors argue may be due to disruption of the stellar dynamo by the massive planet in its close orbit. Over 200 other X-ray sources were also detected in the Chandra image and are listed. The non-detection of X-rays from WASP-18 has implications for models of star-planet interaction and the evolutionary stage of this system.
This document summarizes the discovery of Kepler-413b, a Neptune-sized circumbinary planet orbiting the eclipsing binary star system Kepler-413. The planet has an orbital period of approximately 66 days and an eccentric orbit with a semimajor axis of 0.355 AU. Analysis of the Kepler light curve revealed the planet's orbit is misaligned with the binary star plane by about 2.5 degrees, causing it to sometimes fail to transit one of the stars. The orbital configuration of the system places the planet interior to the habitable zone but its obliquity may undergo fluctuations on precession timescales.
An interacting binary_system_powers_precessing_outflows_of_an_evolved_starSérgio Sacani
1) The authors discovered that the central star system in the planetary nebula Fleming 1 is a binary system with an orbital period of 1.1953 days.
2) They determine that the binary likely consists of a white dwarf primary star with a mass of 0.56-0.7 solar masses and a hotter white dwarf secondary star with a temperature over 120,000 K that provides the ionizing photons to power the nebula.
3) The discovery confirms that binary interactions can explain the precessing outflows and point-symmetric structures seen in Fleming 1 and other planetary nebulae with similar features.
The auroral footprint of enceladus on saturn nature09928Sérgio Sacani
The document reports the detection of magnetic-field-aligned ion and electron beams downstream of Enceladus, indicating electrodynamic coupling between Enceladus and Saturn similar to Io and Jupiter. Auroral ultraviolet emission was observed in Saturn's ionosphere at the footprint location of Enceladus, varying in intensity more than can be explained by changes in magnetospheric parameters alone and likely indicating variable plume activity on Enceladus. The footprint latitude matches predictions based on Saturn's magnetic field model. Flickering of the electron beams between different energy levels was also observed and may be related to standing Alfven waves driven by Enceladus.
An earth mass_planet_orbiting_alpha_centauri_bSérgio Sacani
1) Researchers have detected the smallest minimum mass planet found to date orbiting a solar-type star, Alpha Centauri B.
2) The planet has a minimum mass similar to Earth and orbits Alpha Centauri B with a period of 3.236 days, making it the closest exoplanet to our solar system discovered so far.
3) The detection demonstrates the ability to reach precision needed to detect potentially habitable super-Earth planets around Sun-like stars using radial velocity techniques, though this planet is too close to its star to be habitable.
This document summarizes the discovery of two Earth-sized planets orbiting the star Kepler-20. Precise photometric data from the Kepler spacecraft revealed periodic transit signals indicating planets with sizes of 1.03 times (Kepler-20 e) and 0.87 times (Kepler-20 f) Earth's radius orbiting the star. Statistical analysis shows the planetary interpretation of the transit signals is over three orders of magnitude more likely than alternative hypotheses. The planets are likely rocky in composition.
This document summarizes the discovery of an Earth-mass planet orbiting the star Alpha Centauri B. The planet, with a minimum mass similar to Earth, has an orbital period of 3.236 days and is located about 0.04 astronomical units from the star. High-precision radial velocity measurements from the HARPS spectrograph revealed the planet's signal, making it the lightest planet detected around a solar-type star. The discovery demonstrates that current techniques can detect potentially habitable super-Earth planets around Sun-like stars and habitable Earth-like planets around cooler stars.
An Earth-mass planet orbiting a Centauri BCarlos Bella
1) Researchers detected an Earth-mass planet orbiting the star Alpha Centauri B.
2) The planet has a minimum mass similar to Earth and orbits its star with a period of 3.236 days, within 0.04 astronomical units.
3) This makes it the lightest planet detected orbiting a Sun-like star and the closest exoplanet to our solar system found to date.
1. The document describes the motions of objects in the sky and our location in the universe, including a description of the Milky Way galaxy and our solar system.
2. Key concepts covered include the coordinate systems used to locate celestial objects, precession of the Earth, and the causes of the seasons due to the tilt of the Earth's axis.
3. Motions of objects like the sun and stars are explained, including how the sun appears to move along the ecliptic and causes the seasons as the Earth orbits around it.
Know the star_know_the_planet_discovery_of_l_ate_type_companions_to_two_exopl...Sérgio Sacani
This document summarizes the discovery of additional late-type stellar companions to two exoplanet host stars, HD 2638 and 30 Ari B, using adaptive optics imaging. For both systems, the companions were found to share common proper motion with the primaries, indicating they are physically associated. The estimated orbital periods of the new companions are 130 years for HD 2638 and 80 years for 30 Ari B. This makes 30 Ari B the second confirmed quadruple star system known to host an exoplanet. The discoveries provide additional examples of how binary companions can influence exoplanet dynamics and formation.
Tidal star-planet interaction and its observed impact on stellar activity in ...Sérgio Sacani
This study investigates tidal star-planet interaction by analyzing X-ray observations of planet-hosting stars that are part of wide binary systems. The study compares the X-ray luminosity, an indicator of stellar activity, between the planet-hosting primary star and its non-planet hosting companion star. By analyzing 34 such binary systems with X-ray data from XMM-Newton and Chandra, the study finds that planet hosts with close-in massive planets have higher X-ray luminosity compared to their companion stars, indicating tidal interaction is altering the rotation and magnetic activity of the host stars. The study concludes tidal interaction from massive, close-in planets can impact the rotational evolution of stars, while more distant or smaller planets likely
1) The document reports the discovery of two new circumbinary planets, Kepler-34b and Kepler-35b, orbiting binary star systems.
2) Kepler-34b orbits two sun-like stars every 289 days, while Kepler-35b orbits a pair of smaller stars every 131 days.
3) Analysis of photometric and spectroscopic data confirms the planetary nature of the transiting bodies and determines system parameters like the planets' masses and radii.
Ingrid Stairs: PSR B1620-26 and the Methuselah Planet*JeremyHeyl
This document summarizes research on the millisecond pulsar PSR B1620-26 and its planetary system. Key points include:
- PSR B1620-26 has an inner orbit with a white dwarf companion and an outer orbit with a planetary companion in a wide, eccentric orbit.
- Timing data from 2001-2009 showed an anomaly that disrupted modeling of the dual-Keplerian orbits. Current research aims to fit a full 3-body numerical model to explain this.
- The planetary companion has a mass of about 2.5 Jupiter masses and orbits every 60-1200 years. The white dwarf companion is undermassive and young, at 480 million years old.
-
Micrometeoroid infall onto Saturn’s rings constrains their age to no more tha...Sérgio Sacani
There is ongoing debate as to whether Saturn’s main rings are relatively young or ancient— having been formed
shortly after Saturn or during the Late Heavy Bombardment. The rings are mostly water-ice but are polluted by
non-icy material with a volume fraction ranging from ∼0.1 to 2%. Continuous bombardment by micrometeoroids exogenic to the Saturnian system is a source of this non-icy material. Knowledge of the incoming mass flux
of these pollutants allows estimation of the rings’ exposure time, providing a limit on their age. Here we report
the final measurements by Cassini’s Cosmic Dust Analyzer of the micrometeoroid flux into the Saturnian system.
Several populations are present, but the flux is dominated by low-relative velocity objects such as from the
Kuiper belt. We find a mass flux between 6.9 · 10−17 and 2.7 · 10−16 kg m−2
s
−1 from which we infer a ring exposure time ≲100 to 400 million years in support of recent ring formation scenarios.
1) Cassini images of Saturn's infrared aurora show emission both poleward and equatorward of the main auroral oval, unlike previous ultraviolet observations.
2) The polar emission is highly variable but sometimes as bright as the main oval; it disappears when the main oval has a spiral shape.
3) An arc of emission exists equatorward of the main oval only on the nightside, suggesting internal magnetospheric processes drive this previously unknown current system.
A rocky planet_transiting_a_nearby_low_mass_starSérgio Sacani
Um exoplaneta rochoso do tamanho da Terra, orbita uma estrela pequena e próxima, poderia ser o mundo mais importante já encontrado além do Sistema Solar, disseram os astrônomos.
O planeta localiza-se na constelação de Vela, no hemisfério sul do céu e é próximo o suficiente para que os telescópios possam observar qualquer atmosfera que ele possua, um procedimento que poderia ajudar a registrar algum tipo de vida, se ela existisse em outros planetas, no futuro.
Denominado de GJ 1132b, o exoplaneta é cerca de 16% maior que a Terra, e está localizado a cerca de 39 anos-luz de distância, o que faz com que ele seja três vezes mais próximo da Terra do que qualquer outro exoplaneta rochoso já descoberto. Nessa distância, espera-se que os telescópios sejam capazes de fazer uma análise química de sua atmosfera, a velocidade dos seus ventos e as cores do pôr-do-Sol, que acontecem no exoplaneta.
Os astrônomos registraram o planeta à medida que ele passava na frente da sua estrela, uma estrela do tipo anã vermelha, com somente um quinto do tamanho do Sol. Apesar de muito mais fria e muito mais apagada que o Sol, o GJ 1132b, tem uma órbita tão próxima da estrela que as suas temperaturas superficiais atingem cerca de 260 graus Celsius.
Essa temperatura, obviamente, é muito alta para reter a água em estado líquido na superfície do exoplaneta, fazendo com que ele seja inóspito para a vida, mas não tão quente para queimar toda uma atmosfera que pode ter se formado no planeta.
This document summarizes the discovery of two new circumbinary planets, Kepler-34b and Kepler-35b, found using data from the Kepler spacecraft. Kepler-34b orbits two sun-like stars every 289 days, while Kepler-35b orbits a pair of smaller stars every 131 days. Both planets are gas giants that experience large variations in stellar radiation from the orbital motion of their parent stars. Analysis of Kepler photometry and spectroscopic data determined the orbital and physical parameters of the planets and their host star systems. The discovery of these planets implies that over 1% of close binary star systems have giant planets in aligned orbits, representing millions of planets in the Milky Way galaxy.
Similar to A giant planet around a metal poor star of extragalactic origin (20)
Compositions of iron-meteorite parent bodies constrainthe structure of the pr...Sérgio Sacani
Magmatic iron-meteorite parent bodies are the earliest planetesimals in the Solar System,and they preserve information about conditions and planet-forming processes in thesolar nebula. In this study, we include comprehensive elemental compositions andfractional-crystallization modeling for iron meteorites from the cores of five differenti-ated asteroids from the inner Solar System. Together with previous results of metalliccores from the outer Solar System, we conclude that asteroidal cores from the outerSolar System have smaller sizes, elevated siderophile-element abundances, and simplercrystallization processes than those from the inner Solar System. These differences arerelated to the formation locations of the parent asteroids because the solar protoplane-tary disk varied in redox conditions, elemental distributions, and dynamics at differentheliocentric distances. Using highly siderophile-element data from iron meteorites, wereconstruct the distribution of calcium-aluminum-rich inclusions (CAIs) across theprotoplanetary disk within the first million years of Solar-System history. CAIs, the firstsolids to condense in the Solar System, formed close to the Sun. They were, however,concentrated within the outer disk and depleted within the inner disk. Future modelsof the structure and evolution of the protoplanetary disk should account for this dis-tribution pattern of CAIs.
Signatures of wave erosion in Titan’s coastsSérgio Sacani
The shorelines of Titan’s hydrocarbon seas trace flooded erosional landforms such as river valleys; however, it isunclear whether coastal erosion has subsequently altered these shorelines. Spacecraft observations and theo-retical models suggest that wind may cause waves to form on Titan’s seas, potentially driving coastal erosion,but the observational evidence of waves is indirect, and the processes affecting shoreline evolution on Titanremain unknown. No widely accepted framework exists for using shoreline morphology to quantitatively dis-cern coastal erosion mechanisms, even on Earth, where the dominant mechanisms are known. We combinelandscape evolution models with measurements of shoreline shape on Earth to characterize how differentcoastal erosion mechanisms affect shoreline morphology. Applying this framework to Titan, we find that theshorelines of Titan’s seas are most consistent with flooded landscapes that subsequently have been eroded bywaves, rather than a uniform erosional process or no coastal erosion, particularly if wave growth saturates atfetch lengths of tens of kilometers.
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆Sérgio Sacani
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
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) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
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km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
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Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
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.
Your One-Stop Shop for Python Success: Top 10 US Python Development Providersakankshawande
Simplify your search for a reliable Python development partner! This list presents the top 10 trusted US providers offering comprehensive Python development services, ensuring your project's success from conception to completion.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/how-axelera-ai-uses-digital-compute-in-memory-to-deliver-fast-and-energy-efficient-computer-vision-a-presentation-from-axelera-ai/
Bram Verhoef, Head of Machine Learning at Axelera AI, presents the “How Axelera AI Uses Digital Compute-in-memory to Deliver Fast and Energy-efficient Computer Vision” tutorial at the May 2024 Embedded Vision Summit.
As artificial intelligence inference transitions from cloud environments to edge locations, computer vision applications achieve heightened responsiveness, reliability and privacy. This migration, however, introduces the challenge of operating within the stringent confines of resource constraints typical at the edge, including small form factors, low energy budgets and diminished memory and computational capacities. Axelera AI addresses these challenges through an innovative approach of performing digital computations within memory itself. This technique facilitates the realization of high-performance, energy-efficient and cost-effective computer vision capabilities at the thin and thick edge, extending the frontier of what is achievable with current technologies.
In this presentation, Verhoef unveils his company’s pioneering chip technology and demonstrates its capacity to deliver exceptional frames-per-second performance across a range of standard computer vision networks typical of applications in security, surveillance and the industrial sector. This shows that advanced computer vision can be accessible and efficient, even at the very edge of our technological ecosystem.
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .
Connector Corner: Seamlessly power UiPath Apps, GenAI with prebuilt connectorsDianaGray10
Join us to learn how UiPath Apps can directly and easily interact with prebuilt connectors via Integration Service--including Salesforce, ServiceNow, Open GenAI, and more.
The best part is you can achieve this without building a custom workflow! Say goodbye to the hassle of using separate automations to call APIs. By seamlessly integrating within App Studio, you can now easily streamline your workflow, while gaining direct access to our Connector Catalog of popular applications.
We’ll discuss and demo the benefits of UiPath Apps and connectors including:
Creating a compelling user experience for any software, without the limitations of APIs.
Accelerating the app creation process, saving time and effort
Enjoying high-performance CRUD (create, read, update, delete) operations, for
seamless data management.
Speakers:
Russell Alfeche, Technology Leader, RPA at qBotic and UiPath MVP
Charlie Greenberg, host
Dandelion Hashtable: beyond billion requests per second on a commodity serverAntonios Katsarakis
This slide deck presents DLHT, a concurrent in-memory hashtable. Despite efforts to optimize hashtables, that go as far as sacrificing core functionality, state-of-the-art designs still incur multiple memory accesses per request and block request processing in three cases. First, most hashtables block while waiting for data to be retrieved from memory. Second, open-addressing designs, which represent the current state-of-the-art, either cannot free index slots on deletes or must block all requests to do so. Third, index resizes block every request until all objects are copied to the new index. Defying folklore wisdom, DLHT forgoes open-addressing and adopts a fully-featured and memory-aware closed-addressing design based on bounded cache-line-chaining. This design offers lock-free index operations and deletes that free slots instantly, (2) completes most requests with a single memory access, (3) utilizes software prefetching to hide memory latencies, and (4) employs a novel non-blocking and parallel resizing. In a commodity server and a memory-resident workload, DLHT surpasses 1.6B requests per second and provides 3.5x (12x) the throughput of the state-of-the-art closed-addressing (open-addressing) resizable hashtable on Gets (Deletes).
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
[OReilly Superstream] Occupy the Space: A grassroots guide to engineering (an...Jason Yip
The typical problem in product engineering is not bad strategy, so much as “no strategy”. This leads to confusion, lack of motivation, and incoherent action. The next time you look for a strategy and find an empty space, instead of waiting for it to be filled, I will show you how to fill it in yourself. If you’re wrong, it forces a correction. If you’re right, it helps create focus. I’ll share how I’ve approached this in the past, both what works and lessons for what didn’t work so well.
Fueling AI with Great Data with Airbyte WebinarZilliz
This talk will focus on how to collect data from a variety of sources, leveraging this data for RAG and other GenAI use cases, and finally charting your course to productionalization.
How information systems are built or acquired puts information, which is what they should be about, in a secondary place. Our language adapted accordingly, and we no longer talk about information systems but applications. Applications evolved in a way to break data into diverse fragments, tightly coupled with applications and expensive to integrate. The result is technical debt, which is re-paid by taking even bigger "loans", resulting in an ever-increasing technical debt. Software engineering and procurement practices work in sync with market forces to maintain this trend. This talk demonstrates how natural this situation is. The question is: can something be done to reverse the trend?
Discover top-tier mobile app development services, offering innovative solutions for iOS and Android. Enhance your business with custom, user-friendly mobile applications.
The Microsoft 365 Migration Tutorial For Beginner.pptxoperationspcvita
This presentation will help you understand the power of Microsoft 365. However, we have mentioned every productivity app included in Office 365. Additionally, we have suggested the migration situation related to Office 365 and how we can help you.
You can also read: https://www.systoolsgroup.com/updates/office-365-tenant-to-tenant-migration-step-by-step-complete-guide/
What is an RPA CoE? Session 1 – CoE VisionDianaGray10
In the first session, we will review the organization's vision and how this has an impact on the COE Structure.
Topics covered:
• The role of a steering committee
• How do the organization’s priorities determine CoE Structure?
Speaker:
Chris Bolin, Senior Intelligent Automation Architect Anika Systems
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Harnessing the Power of NLP and Knowledge Graphs for Opioid Research
A giant planet around a metal poor star of extragalactic origin
1. A Giant Planet Around a Metal-Poor Star of Extragalactic Origin
Johny Setiawan,1 Rainer J. Klement,1 Thomas Henning,1 Hans-Walter Rix,1 Boyke Rochau,1 Jens
Rodmann,2 Tim Schulze-Hartung1
1
Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany. 2European Space Agency, Space
Environment and Effects Section, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, Netherlands.
To whom correspondence should be addressed. E-mail: setiawan@mpia.de
Stars in their late stage of evolution, such as Horizontal formation mechanism of this particular planet might be linked
Branch stars, are still largely unexplored for planets. We to the dense cluster environment (7).
report the detection of a planetary companion around We used the Fibre-fed Extended Range Optical
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HIP 13044, a very metal-poor star on the red Horizontal Spectrograph (FEROS), a high-resolution spectrograph (R =
Branch, based on radial velocity observations with a high- 48,000) attached to the 2.2 meter Max-Planck
resolution spectrograph at the 2.2-m MPG/ESO telescope. Gesellschaft/European Southern Observatory (MPG/ESO)
The star's periodic radial velocity variation of P = 16.2 telescope (8), to observe the star HIP 13044. This star is
days caused by the planet can be distinguished from the classified as a red HB (RHB) star (Fig. 1) and its metal
periods of the stellar activity indicators. The minimum content is [Fe/H]mean = 2.09 (9––12), i.e. about 1% that of the
mass of the planet is 1.25 Mjup and its orbital semi-major Sun. So far, HIP 13044 is not known as a binary system.
axis 0.116 AU. Because HIP 13044 belongs to a group of Detailed stellar parameters can be found in Supporting Online
stars that have been accreted from a disrupted satellite Material (SOM) text 1.
galaxy of the Milky Way, the planet most likely has an Previous radial velocity (RV) measurements of HIP 13044
extragalactic origin. showed a systematic velocity of about 300 km s 1 with
respect to the Sun, indicating that the star belongs to the
In the last two decades, several hundred planets have been
stellar halo (13). Indeed, the star has been connected to the
detected beyond our Solar-system. Most of these extra-solar
Helmi stream (14), a group of stars that share similar orbital
planets orbit sun-like stars. A small number have been
parameters that stand apart from those of the bulk of other
detected around stars that are in their late evolutionary state,
stars in the solar neighborhood. The Helmi stream stars move
such as Red Giant Branch (RGB) stars and pulsars. The phase
on prograde eccentric orbits (Rperi 7 kpc, Rapo 16 kpc) that
directly after the RGB stage, the Horizontal Branch (HB),
reach distances up to |z|max 13 kpc above and below the
however, is still unexplored; therefore, there is no empirical
galactic plane. From that, it has been concluded that these
evidence for whether close-in planets, i.e., those with semi-
stars were once bound to a satellite galaxy of the Milky Way
major axes less than 0.1 AU, survive the giant phase of their
(10, 14) that was tidally disrupted 6-9 Ga ago (15).
host stars.
The variation of the RV between our observations at
Besides its evolutionary stage, a star's chemical
different epochs has a semi-amplitude of 120 m s 1 (16) (Fig.
composition appears to be a major indicator of its probability
2). The Generalized Lomb Scargle (GLS) periodogram (17)
for hosting a planet. Previous studies, e.g., (1), showed that
reveals a significant RV periodicity at P = 16.2 days with a
main-sequence (MS) stars that host giant planets are metal-
False Alarm Probability of 5.5 × 10 6. Additional analysis,
rich. This finding is supported by the large exoplanet search
using a Bayesian algorithm (18), yields a similar period
surveys around MS stars reporting a connection between
around 16 days. Such RV variation can be induced by an
planet frequency and metallicity (2, 3), and a survey of 160
unseen orbiting companion, by moving/rotating surface
metal-poor main-sequence stars finding no evidence for
inhomogeneities or by non-radial stellar pulsations. Exploring
Jovian planets (4).
both stellar rotational modulation and pulsations is critical
Until now, only very few planets have been detected
when probing the presence of a planetary companion, because
around stars with metallicities as low as [Fe/H] = 1, i.e. 10%
they can produce a similar or even the same RV variation,
of the sun's metallicity. The detection of PSR B1620 b, a
mimicking a Keplerian motion.
Jovian planet orbiting a pulsar in the core of the metal-poor
A well-established technique to detect stellar rotational
globular cluster M4 ([Fe/H] = 1.2), suggests, however, that
modulation is to investigate the line profile asymmetry or
planets may form around metal-poor stars (5, 6), although the
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2. bisector (19) and Ca II lines (SOM text 3). Surface signal. What is important, however, is that there is no signal
inhomogeneities, such as starspots and large granulation cells, of a period around 16.2 days in the photometric data.
produce asymmetry in the spectral line profiles. When a The arguments above show that neither stellar rotational
spotted star rotates, the barycenter of the line profiles moves modulation nor pulsations are plausible sources of the
periodically and the variation can mimic a RV variation observed periodic RV variation. Therefore, the best
caused by an orbiting companion. Instead of measuring the explanation for the 16 days period is the presence of an
bisectors, one can equivalently use the bisector velocity spans unseen companion. We computed its orbital solution (Table
(BVS) to search for rotational modulation (20). Adopting this 1). Its minimum mass lies securely in the planetary mass
technique, we have measured BVS from the stellar spectra. domain, even with a plausible sini uncertainty. With an
There is only a weak correlation between BVS and RV eccentricity of 0.25 and a semi-major axis of 0.116 AU, the
(correlation coefficient = 0.13), but the BVS variation shows planet has a periastron distance of about 0.087 AU which is
a clear periodicity with P = 5.02 days (SOM text 3.1.1). No 2.8 times the present stellar radius. The periastron is 0.06
period around 16 days is found in the BVS variation. AU away from the stellar surface.
In addition to the BVS analysis, we investigated the Because a large number of known exoplanets have orbital
variation of the Ca II 849.8 line, which is one of the Ca II semi-major axes between 0.01 and 0.06 AU, the distance
infrared triplet lines. From the observed Ca II 849.8 between the periastron and the star HIP 13044 itself is not
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equivalent-width variations we computed a mean period of unusual. The non-circular orbit (e = 0.25), however, is not
6.05 days (SOM text 3.1.2), which is in the same order of the expected for a close-in giant planet around a post RGB star.
period of the BVS variation. We adopted the mean period of In the case of HIP 13044, the original orbit could have
both stellar activity indicators, Prot = 5.53 ± 0.73 days, as the been disturbed or changed during the evolution of the star-
stellar rotation period of HIP 13044 and then calculated the planet-system, in particular during the RGB phase (22).
inclination angle of the stellar rotation axis, which follows Interestingly, the orbital period of HIP 13044 b is close to
from Prot/sini = 2 R* /v sini. With a stellar radius R* = 6.7 R three times the stellar rotation period. There are a number of
(21) and our adopted value for the projected rotational known planetary systems which also have such a "coupling"
velocity, v sini = 10.25 km s 1, which was derived from the between the stellar rotation and orbital periods, e.g. Tau Boo
observed line broadening (SOM text 1), we obtained an (1:1), HD 168433 (1:2), HD 90156 (1:2) and HD 93083 (1:3).
inclination angle i = 9.7 ± 1.3 deg. Thus, the real stellar Such planetary systems are particularly interesting to study
rotation velocity is 62 km s 1, which is typical for an early star-planet interactions (30).
F type MS-star but relatively high for HB stars. So far, there are only very few planet or brown dwarf
An explanation for this high rotation velocity is the detections around post RGB stars besides the pulsar planets,
assumption that HIP 13044 has engulfed its close-in planets namely V391 Peg (31), HW Vir (32) and HD 149382 (33)
during the red giant phase. Infalling planets are able to spin- (Fig. 1). These are, however, substellar companions around
up their host star (22––24), and this mechanism has been subdwarf-B or Extreme Horizontal Branch (EHB) stars, i.e.,
suggested to explain the high v sini values observed for many the nature of their host stars differs from that of HIP 13044,
RGB and HB stars (25). an RHB star. Contrary to RGB stars, such as G and K giants
We observed variations of HIP 13044 in the photometric (34––37) and subgiants, e.g. (38), HB stars have not been yet
data from the Hipparcos satellite (26) and SuperWASP (27) extensively surveyed for planets.
(SOM text 3.2.4). While the Hipparcos data shows only a While at least 150 main-sequence stars are known to bear
marginal significant periodicity of 7.1 hours (FAP = 1.8%), close-in (a = 0.1 AU) giant planets, so far no such planets
the SuperWASP data shows few intra-day periodicities with have been reported around RGB stars. A possible explanation
FAP 1% and two significant periodicities at 1.39 (FAP = 5 is that the inner planets have been engulfed by the star when
× 10 4) and 3.53 days (FAP = 2 × 10 4). These two periods, the stellar atmosphere expanded during the giant phase. The
however, are most likely harmonic to each other (1.4 1 + 3.5 1 survival of HIP 13044 b during that phase is theoretically
= 1). It is expected that HIP 13044 oscillates only at possible under certain circumstances (22, 39, 40). It is also
pulsationally unstable overtones of high order (28). possible that the planet's orbit decayed through tidal
Observations of one RHB star in the metal-poor globular interaction with the stellar envelope. However, a prerequisite
cluster NGC 6397 (29) as well as theoretical predictions (28) to survival is then that the mass loss of the star stops before
set these periods in the range of a few hours to a day or so. the planet would have been evaporated or accreted. Assuming
No clear theoretical predictions for a star with parameters asymmetric mass loss, velocity kicks could have increased
similar to HIP 13044 exist, hence it is possible that some the eccentricity of HIP 13044 b to its current, somewhat high
high-order oscillations are able to explain the 1.4 or 3.5 day value (41). The same could be achieved by interaction with a
third body in the system.
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3. Interestingly, a survey to characterize the multiplicity of 8. The observations of HIP 13044 were carried out from
EHB stars showed that more than 60% of the sample are September 2009 until July 2010. The spectrograph covers
close binaries (42). Their orbital radii are much smaller than a wavelength range from 350 to 920 nm (48). To measure
the stellar radius in the RGB phase. This could be explained the RV values of HIP 13044 we used a cross-correlation
by the high friction in the interstellar medium, which would technique, where the stellar spectrum is cross-correlated
move a distant companion towards the primary. Such spiral- with a numerical template (mask) designed for stars of the
in mechanism could also take place in the RGB-to-RHB spectral type F0 (SOM text 2).
transition phase. Similar to the binary case, a distant giant 9. T. C. Beers, J. A. Kage, G. W. Preston, S. A. Shectman,
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2
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49. We thank our MPIA colleagues: W. Wang, C. Brasseur, m2 sini 1.25 ± 0.05 MJup
R. Lachaume, M. Zechmeister and D. Fedele for the a 0.116 ± 0.01 AU
spectroscopic observations with FEROS. We also thank
Dr. M. Perryman, Dr. E. Bear, Dr. N. Soker and Dr. P.
Maxted for the fruitful discussion, comments and
suggestions that helped to improve this paper.
Supporting Online Material
www.sciencemag.org/cgi/content/full/science.1193342/DC1
SOM Text
Figs. S1 to S6
Tables S1 and S2
References
7 June 2010; accepted 10 November 2010
Published online 18 November 2010;
10.1126/science.1193342
Fig. 1. Location of HIP 13044 in a MV vs. B V color-
magnitude diagram (CMD) shown as a black dot
superimposed to the CMD of Messier 3 (grey open circles)
based on the photometry by (46). Apparent magnitudes have
been converted to absolute magnitudes by considering the
distance modulus and extinction given by Harris (47). The
gap separating the blue and red Horizontal Branch (HB) is
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