Question 1·   What characteristic of Cepheid variables makes th.docx

Question 1
· What characteristic of Cepheid variables makes them
extremely useful to astronomers?
·
· 1.
· The absolute magnitude of Cepheid variables is related
directly to their surface
· temperature.
·
·
· 2.
· The absolute magnitude of Cepheid variables is directly
related to their diameter.
·
· 3.
directly to their period of
· pulsation.
·
·
· 4.
directly to their metal
· content (heavy element abundance).
·
1 points
Question 2
· What is the most important process that causes a protostar
to stop accreting mass?
·
· 1.
· All of the infalling matter has been used up in the accretion.
·
· 2.

· Radiation and particles from the hot protostar push infalling
matter away from
· the protostar.
·
·
· 3.
· Other protostars formed in the vicinity pass randomly through
the infalling
· material and eventually disperse it.
·
·
· 4.
· The dense core spins up as it collapses, and eventually the
infalling matter is
· held away from the protostar by the centrifugal force.
·
1 points
Question 3
· The definition of a main-sequence star is a star
·
· 1.
· whose age after birth is about 1 million years.
·
· 2.
· with a luminosity precisely equal to that of the Sun.
·
· 3.
· in which nuclear fusion reactions generate sufficient energy to
oppose further
· condensation of the star.
·
·
· 4.
· with a surface temperature equal to that of the Sun.
·
1 points

Question 4
· Which of the following stars would you classify as a
Population II star?
·
· 1.
· star with approximately the same abundance of heavy elements
that we find in the Sun
·
· 2.
· star with very low abundance of heavy elements
·
· 3.
· star with much higher abundance of heavy elements than we
find in the Sun
·
· 4.
· star in an open star cluster
·
1 points
Question 5
· The light from a distant cloud of gas and dust looks
distinctly red to the unaided eye. When a spectrum is taken, the
red color is found to come from a single, bright spectral line.
Thus the red color in this situation is due to
·
· 1.
· interstellar reddening, the Balmer spectrum of hydrogen, or
the Doppler effect.
·
· 2.
· interstellar reddening.
·
· 3.
· the Doppler effect.
·
· 4.

· the Balmer spectrum of hydrogen.
·
1 points
Question 6
· New stars are formed from
·
· 1.
· hot supernova remnants.
·
· 2.
· pure energy in free space.
·
· 3.
· activity around black holes in the centers of galaxies.
·
· 4.
· huge, cool dust and gas clouds.
·
1 points
Question 7
· If you were to look at 1 kilogram of material taken from
the surface of the Sun and 1 kilogram taken from the center,
which of the following statements would be true of the two
kilograms?
·
· 1.
· Both kilograms have the same amount of hydrogen and are in
fact mostly hydrogen.
·
· 2.
· The kilogram from the surface contains more hydrogen than
the one from the center.
·
· 3.
· Neither kilogram contains any hydrogen.
·

· 4.
· The kilogram from the surface contains less hydrogen than the
one from the center.
·
1 points
Question 8
· How is the length of a star's lifetime related to the mass of
the star?
·
· 1.
· Lower-mass stars run through their lives faster and have
shorter lifetimes.
·
· 2.
· Higher-mass stars run through their lives faster and have
shorter lifetimes.
·
· 3.
· The lifetimes of stars are too long to measure, so it is not
known how (or if) their
· lifetimes depend on mass.
·
·
· 4.
· A star's lifetime does not depend on its mass.
·
1 points
Question 9
· How do the stars in a star cluster change with time?
·
· 1.
· All stars in a cluster evolve at the same rate.
·
· 2.
· The highest-mass stars evolve the most quickly.
·

· 3.
· The stars with the greatest heavy element content evolve the
most quickly.
·
· 4.
· The lowest-mass stars evolve the most quickly.
·
1 points
Question 10
· During helium burning in a star's later life, the chemical
element produced by the combination of helium nuclei is
·
· 1.
· the light isotope of helium, 3He.
·
· 2.
· carbon, 12C.
·
· 3.
· heavy hydrogen, 2H.
·
· 4.
· beryllium, 8Be.
Question 11
· What quantum transition occurs inside a hydrogen atom to
produce a 21-cm radio photon? Answer
·
· 1.
· An electron in the ground atomic state reverses its direction of
spin with
· respect to that of the proton.
·
·
· 2.
· An electron falls from the level n = 100 to the level n = 99 in

the atom.
·
· 3.
· An electron reverses the direction of its motion in orbit around
the proton.
·
· 4.
· The electron combines with the proton in the nucleus to
become a neutron,
· producing energy.
·
1 points
Question 12
· What happens when the electron in a hydrogen atom flips
its direction of spin from parallel to antiparallel to that of the
proton? Answer
·
· 1.
· The atom emits a photon of 21-cm wavelength in the radio
region of the spectrum.
·
· 2.
· The atom emits a photon of 121.5-nm wavelength (Lα) in the
UV region of the spectrum.
·
· 3.
· Nothing. This event is a forbidden transition that never occurs.
·
· 4.
· The atom emits a photon of 656.3-nm wavelength (Hα) in the
red region of the spectrum.
·
1 points
Question 13
· Why are we on Earth able to see only a relatively small
part of the Milky Way Galaxy? Answer

·
· 1.
· Distant stars are obscured by dust in interstellar space.
·
· 2.
· Expansion of the universe has carried the more distant stars
out of our view.
·
· 3.
· Distant stars are obscured by gas in interstellar space.
·
· 4.
· There are so many stars in the Milky Way that the more
distant ones are hidden
· behind the nearer ones.
·
1 points
Question 14
· The stars in the Milky Way Galaxy Answer
·
· 1.
· number between 8 and 10 million.
·
· 2.
· move generally around the galactic center.
·
· 3.
· are all receding from the galactic center.
·
· 4.
· obey Hubble's law of recession.
·
1 points
Question 15
· Which of the following components of the Milky Way
Galaxy outlines the spiral arms of the Galaxy? Answer

·
· 1.
· white dwarf stars
·
· 2.
· young O and B stars, dust, and gas
·
· 3.
· predominantly solar-type stars
·
· 4.
· globular clusters
·
1 points
Question 16
· What fraction of the mass of the Milky Way Galaxy
appears to be in the form of “dark matter,” which we cannot see
but can detect through its gravitational influence? Answer
·
· 1.
· 0%—who ever heard of matter that can't be seen?
·
· 2.
· about 10%
·
· 3.
· about 50%
·
· 4.
· about 90%
·
1 points
Question 17
· Where is the Sun located in the Milky Way Galaxy? (That
is, what is the address of the Sun in the universe?) (See Figure
15-9 of Comins and Kaufmann, Discovering the Universe, 8th

ed.) Answer
·
· 1.
· in the Sagittarius arm, between the Centaurus and Orion arms
·
· 2.
· in the Centaurus arm, between the galactic center and the
Orion arm
·
· 3.
· in or close to the Orion arm, between the Sagittarius and
Perseus arms.
·
· 4.
· in the Perseus arm, between the Orion and Cygnus arms
·
1 points
Question 18
· The first suggestion that there were collections of stars
beyond the Milky Way in the universe was made by Answer
·
· 1.
· Edwin Hubble in 1923.
·
· 2.
· Sir Isaac Newton in 1690.
·
· 3.
· William Parsons, Earl of Rosse, in 1845.
·
· 4.
· Immanuel Kant in 1755.
·
1 points
Question 19
· Where in space would you look for a globular cluster?

Answer
·
· 1.
· in the asteroid belt
·
· 2.
· in elliptical galaxies since they are composed of old stars and
do not exist in
· young systems like spiral galaxies
·
·
· 3.
· in the Milky Way galactic halo, orbiting the galactic center in
a long elliptical
· orbit around the galactic center
·
·
· 4.
· in the Milky Way disk, moving in a circular orbit around the
galactic center
·
1 points
Question 20
· Interstellar matter obscures our view of the disk of the
Milky Way Galaxy Answer
·
· 1.
· most at radio wavelengths, where hydrogen absorbs radio
waves efficiently, and
· least at optical wavelengths.
·
·
· 2.
· very little at any wavelength.
·
· 3.

· more or less equally at all wavelengths, from radio waves to
light waves.
·
· 4.
· more at optical wavelengths and less or not at all at infrared
and radio wavelengths.
Question 21
· Even though cosmic microwave background photons
outnumber hydrogen atoms by about 1 billion to 1 in the
universe, the universe is still considered to be matter-dominated
because the
·
· 1.
· photon energies are extremely small.
·
· 2.
· photons have no rest mass and hence can generate no gravity.
·
· 3.
· nature of the photons is such that they interact with nothing as
they pass
· through the universe.
·
·
· 4.
· photons, while collectively carrying a large amount of energy,
do not carry an
· equivalent amount of momentum and hence play little role in
collisions with matter.
·
1 points
Question 22
· What appears to be the relationship between the
distribution of dark matter and the distribution of luminous
matter?

·
· 1.
· There seems to be no correlation at all.
·
· 2.
· The distribution of dark matter seems to coincide with the
distribution of luminous
· matter.
·
·
· 3.
· There seems to be a separate distribution of dark matter—
dark-matter galaxy
· clusters, voids in the dark matter, and so on. But these
formations all occur in
· regions of space far from luminous matter.
·
·
· 4.
· The distribution of dark matter seems to be just the reverse of
the distribution of
· luminous matter: Dark-matter galaxy clusters occur in the
voids of luminous matter;
· luminous galaxy clusters occur in the voids of dark matter.
·
1 points
Question 23
· How does the observed total amount of matter in the
universe, including dark matter, compare with the amount of
matter required to just close the universe?
·
· 1.
· The observed total amount of matter is about twice the amount
needed.
·
· 2.

· The observed total amount of matter equals the amount
needed, to within
· observational uncertainty.
·
·
· 3.
· The observed total amount of matter is about 1/200 of the
amount needed.
·
· 4.
· The observed total amount of matter is about 1/3 of the
amount needed.
·
1 points
Question 24
· Which of the following cosmological problems is “dark
energy” believed to solve?
·
· 1.
· Why did the universe suddenly inflate during the Big Bang?
·
· 2.
· Why is the temperature of the cosmic background radiation so
smooth (isotropic)
· around the sky?
·
·
· 3.
· Why is the night sky dark?
·
· 4.
· Why is the universe flat?
·
1 points
Question 25
· What is the range of the strong nuclear force compared

with the size of the nucleus, 10–14 m?
·
· 1.
· infinite; it has no limit
·
· 2.
· 10 times larger than the size of an atomic nucleus
·
· 3.
· 10 times smaller than the size of an atomic nucleus
·
· 4.
· same since it is the strong force that holds the nucleus
together
·
1 points
Question 26
· Einstein introduced a “cosmological constant” into his
formulation of the structure of the universe as described by his
general theory of relativity. How did he envision that this
cosmological constant would manifest itself?
·
· 1.
· as antimatter that, by annihilating real matter, would translate
matter into energy,
· thereby maintaining a constant mass density in a condensing
universe
·
·
· 2.
· as a form of energy that, on its own, would make the universe
expand—a form of
· antigravity
·
·
· 3.

· as many “white holes” that would contribute matter to an
expanding universe to
· maintain constant density, as required by the cosmological
principle—a continuous
· creation universe
·
·
· 4.
· as an extra “gravity” that would hold the universe against
continuous expansion
·
1 points
Question 27
· At what time did the universe cool to a temperature of
about 3 K?
·
· 1.
· end of the Planck time
·
· 2.
· end of the inflationary era
·
· 3.
· very recently
·
· 4.
· era of recombination
·
1 points
Question 28
· What is the period of quark confinement?
·
· 1.
· Because of the very large pressure in early times, all the
quarks were confined
· to a small volume. After the inflationary, epoch the pressure

dropped and the
· quarks were able to spread out to assume the distribution we
find today.
·
·
· 2.
· During the period of quark confinement, the energy of the
photons was sufficiently
· high that conglomerations of quarks, such as neutrons and
protons, could not
· exist and quarks were free.
·
·
· 3.
· to the period of quark confinement was the very early period
in the universe when
· all matter and energy were confined to a region the size of a
single quark.
·
·
· 4.
· During the period of quark confinement, the energy of the
photons was sufficiently
· low that conglomerations of quarks, such as neutrons and
protons, could exist
· without being blasted apart as soon as they were formed.
·
1 points
Question 29
· During the first one-ten-thousandth of a second (10–4 s) of
the life of the universe, antiprotons were very common. For
every billion antiprotons, how many protons were there?
·
· 1.
· exactly 1 billion since protons and antiprotons were created in
equal numbers

·
· 2.
· slightly more than 1 billion, thus producing the matter we see
today
·
· 3.
· 10 billion, thus producing the dark matter we see today
·
· 4.
· totally unknown number since the early universe was opaque
and we cannot see
· what conditions were like then
·
1 points
Question 30
· How does the cosmological constant differ from
quintessence?
·
· 1.
· There is essentially no difference; basically, quintessence is
the modern name for
· the cosmological constant.
·
·
· 2.
· The cosmological constant provides a constant accelerating
force in the universal
· expansion, whereas quintessence can change as the expansion
proceeds.
·
·
· 3.
· The cosmological constant provides an accelerating force in
the universal expansion,
· whereas quintessence provides a decelerating term; it is the
balance between the

· cosmological constant and quintessence that determines
whether the expansion
· accelerates or decelerates.
·
·
· 4.
· The cosmological constant is a specific physical effect that
can be described
· mathematically, whereas quintessence is the total of all
indefinable properties
· that make the universe what it is at any given time.
Question 31
· There is very little hydrogen or helium in the inner part of
the solar system today. We believe the reason for this is that
Answer
·
· 1.
· the intense radiation from the early Sun drove the light
elements out of the
· inner solar system.
·
·
· 2.
· all the light elements went into the formation of the Sun itself
and little were
· left over for the rest of the solar system.
·
·
· 3.
· heavier elements were attracted in from the outer part of the
solar system,
· displacing the light elements originally in the inner part.
·
·
· 4.

· the light elements underwent chemical reactions and were
locked up in
· chemicals in the inner solar system.
·
1 points
Question 32
· Moons have been discovered around Answer
·
· 1.
· just the terrestrial planets.
·
· 2.
· just the Jovian planets.
·
· 3.
· all the planets.
·
· 4.
· all the planets except those nearer to the Sun than Earth is.
·
1 points
Question 33
· Each of the following descriptions except one is believed
to be a possible mechanism that can trigger the collapse of a
cloud of gas and dust to form a star. Which is the exception?
Answer
·
· 1.
· Stellar winds may compress nearby gas and dust clouds.
·
· 2.
· A nearby supernova can compress nearby gas and dust clouds.
·
· 3.
· Clouds can collide and compress each other.
·

· 4.
· Radiation pressure from the Cosmic Microwave Background
can compress
· clouds of gas and dust.
·
1 points
Question 34
· The planet whose average density is less than that of water
is Answer
·
· 1.
· Saturn.
·
· 2.
· Jupiter.
·
· 3.
· Neptune.
·
· 4.
· Earth.
·
1 points
Question 35
· Which planet in our solar system has the lowest average
density? Answer
·
· 1.
· Uranus
·
· 2.
· Earth
·
· 3.
· Saturn
·

· 4.
· Jupiter
·
1 points
Question 36
· How do we measure the mass of an extrasolar planet?
Answer
·
· 1.
· We cannot make any firm estimate of the mass of an extrasolar
planet
· with present technology.
·
·
· 2.
· We measure the planet's angular diameter and hence its size
and then use
· spectra to find its composition and hence density.
·
·
· 3.
· We use Newton's law of gravity, using the measured distance
of the planet
· from its star and the planet's gravitational pull on the star
·
·
· 4.
· We use spectra to measure the planet's temperature and
photometry to
· measure its brightness.
·
1 points
Question 37
· What are the three “common” substances that are believed
to be important in planet formation? Answer
·

· 1.
· rock, ices, and gas
·
· 2.
· electromagnetic radiation, electrical discharges (e.g.,
lightning), and water
·
· 3.
· solid, liquid, and gaseous hydrogen
·
· 4.
· hydrogen, helium, and neon gases
·
1 points
Question 38
· In our solar system, which of the following planets is a
member of the terrestrial group? Answer
·
· 1.
· Neptune
·
· 2.
· Mars
·
· 3.
· Saturn
·
· 4.
· Jupiter
·
1 points
Question 39
· Pluto was originally classified as a planet, but new criteria
for the definition of a planet were adopted, and Pluto failed to
meet one of them. Which one? Answer
·

· 1.
· Pluto does not have enough gravity to clear its orbit.
·
· 2.
· Pluto does not orbit the Sun directly.
·
· 3.
· Pluto does not spin fast enough to produce its own magnetic
field.
·
· 4.
· Pluto does not have enough mass to pull itself into a roughly
spherical shape.
·
1 points
Question 40
· Which of the following statements is true? Answer
·
· 1.
· Earth is the most massive of the terrestrial planets.
·
· 2.
· Jupiter has the highest average density of the planets.
·
· 3.
· The average mass of terrestrial planets is close to the average
mass of the
· large, outer planets.
·
·
· 4.
· Earth is the biggest of the planets.
Question 41
· The lunar maria appear smooth because they are
Answer

·
· 1.
· regions where craters have been obliterated by crustal
deformation caused by
· hot spots and volcanic lava flow from the underlying molten
mantle.
·
·
· 2.
· recent lava flows, occurring within the last billion years, that
have obliterated
· earlier craters.
·
·
· 3.
· ancient lava flows that occurred soon after the end of an early
period of intense
· bombardment and that have had relatively few impacts since
then.
·
·
· 4.
· ancient sea beds, now dry, dating back to when the Moon had
a denser
· atmosphere and rainfall was abundant.
·
1 points
Question 42
· What is the ratio of nitrogen to oxygen in Earth's
atmosphere? Answer
·
· 1.
· equal parts nitrogen and oxygen
·
· 2.
· 1 part nitrogen to 4 parts oxygen

·
· 3.
· 1 part nitrogen to 2 parts oxygen
·
· 4.
· 4 parts nitrogen to 1 part oxygen
·
1 points
Question 43
· Which of the following models of Earth's interior is now
considered to be the most likely description of the actual Earth?
Answer
·
· 1.
· totally fluid interior rotating at the same rate as the outer
mantle and crust
·
· 2.
· solid core within a molten outer core, the whole system
rotating at exactly
· the same rate as the outer mantle and crust
·
·
· 3.
· solid core rotating more rapidly than the rest of Earth within a
molten outer core
·
· 4.
· solid core rotating more slowly than the rest of Earth within a
molten outer core
·
1 points
Question 44
· What is the origin of the majority of lunar craters?
Answer
·

· 1.
· impacts by space probes from Earth
·
· 2.
· surface collapse after loss of groundwater by evaporation
·
· 3.
· impacts by meteoric material
·
· 4.
· volcanic explosions
·
1 points
Question 45
· Which scientific approach gives us the most information
about the deep interior of Earth? Answer
·
· 1.
· worldwide measurement of low-frequency seismic waves
produced by earthquakes
·
· 2.
· deep drilling of exploratory holes for science and mineral
recovery (e.g., oil)
·
· 3.
· measurement of cosmic neutrinos, which pass very easily
through Earth
·
· 4.
· study of lava flows from volcanoes
·
1 points
Question 46
· Earth's mantle, the semimolten layer below the crust, is
composed largely of what chemical materials? Answer

·
· 1.
· amost pure iron
·
· 2.
· minerals rich in iron and magnesium
·
· 3.
· solid hydrogen and helium
·
· 4.
· iron-poor rocks and minerals
·
1 points
Question 47
· What are spring tides? Answer
·
· 1.
· high tides that are significantly higher than the average high
tide
·
· 2.
· high tides that are significantly lower than the average high
tide
·
· 3.
· any low tides
·
· 4.
· any high tides
·
1 points
Question 48
· The core (inner and outer) of Earth extends over what
fraction of its radius? Answer
·

· 1.
· about
·
· 2.
· almost 80%
·
· 3.
· less than 10%
·
· 4.
· roughly
·
1 points
Question 49
· Which two tectonic plates are slowly separating from each
other on Earth's surface along the Mid-Atlantic Ridge in the
South Atlantic? (See Figure 6-7, Comins and Kaufmann,
Discovering the Universe, 8th ed.) Answer
·
· 1.
· Pacific and Australia-India plates
·
· 2.
· South American and African plates
·
· 3.
· African and Eurasian plates
·
· 4.
· Nazca and Pacific plates
·
1 points
Question 50
· What is the diameter of the Moon compared with the
diameter of Earth? Answer
·

· 1.
· about 1/10 of the diameter of Earth
·
· 2.
· less than 1/100 of the diameter of Earth
·
· 3.
· just over 1/2 the diameter of Earth
·
· 4.
· about 1/4 of the diameter of Earth
Question 1
· The first successful detection of signals from
extraterrestrial civilizations was accomplished in which year?
Answer
·
· 1.
· 1960
·
· 2.
· Never—no such signals have been detected yet.
·
· 3.
· 1999
·
· 4.
· 1985
·
1 points
Question 2
· The meteorite ALH 84001 was discovered in Antarctica in
1984. Some researchers claimed that it came from Mars and that
it showed fossilized evidence of life. At the present time the

scientific community is in general agreement that this meteorite
Answer
·
· 1.
· came from Mars.
·
· 2.
· does not contain fossilized life forms.
·
· 3.
· came from Mars and contains fossilized life forms.
·
· 4.
· contains fossilized life forms.
·
1 points
Question 3
· One of the great lessons being learned from modern
astronomy is that Answer
·
· 1.
· Earth's position and circumstances in the universe are quite
ordinary and certainly
· not unique.
·
·
· 2.
· Earth occupies a unique position in the universe, and nowhere
else are conditions
· equivalent to those in the solar system likely to be found.
·
·
· 3.
· Earth is at the center of a very massive black hole, and all the
observed
· cosmological effects such as redshift and cosmic background

radiation and
· even the evolution of life are a consequence of the unique
position Earth occupies.
·
·
· 4.
· the chemistry, geology, and physics on Earth are unique to our
planet, and the
· behavior of matter anywhere else appears to be significantly
different from that
· on Earth.
·
1 points
Question 4
· The so-called water hole, a region of the radio spectrum
chosen for searches for signals from intelligent life because
galactic and Earth-based noise and atmospheric absorption are
at a minimum, is so named because Answer
·
· 1.
· water vapor (H2O) has an intense laserlike emission line at
this wavelength that
· extraterrestrials might use to communicate with us.
·
·
· 2.
· two astronomically important wavelengths, the 21-cm line of
H and a line from
· the hydroxyl radical OH, are in this region, the letters H and
OH signifying water.
·
·
· 3.
· water vapor absorption in Earth's atmosphere reaches a sharp
minimum at this
· wavelength.

·
·
· 4.
· water vapor emissions from planets at this wavelength will be
a good indicator
· of life on other planets since water is essential for life as we
know it.
·
1 points
Question 5
· Which of the following observations regarding the
likelihood of life existing elsewhere in the universe has NOT
yet been made? Answer
·
· 1.
· discovery of assemblies of organic molecules into cell-like,
self-replicating
· structures in the soils of Mars and the atmosphere of Venus
·
·
· 2.
· discovery of long-chain amino acid protein molecules in
meteorites
·
· 3.
· discovery of long-chain carbon-based molecules in interstellar
clouds by radio
· astronomers
·
·
· 4.
· manufacture of organic compounds in laboratory simulations
of primordial
· planetary atmospheres
·
1 points

Question 6
· Why is it highly likely that life, should it exist elsewhere
in the universe than just on Earth, would be based on carbon
chemistry? Answer
·
· 1.
· Carbon is expected to be far more abundant than silicon or
other like elements
· that can combine to produce complex molecules.
·
·
· 2.
· Carbon combines more readily than other atoms with nitrogen,
the major
· component of atmospheres such as that of Earth, to produce
complex molecules.
·
·
· 3.
· Carbon releases more energy than do most other atoms when it
combines with
· oxygen, providing the energy for life processes in living
organisms.
·
·
· 4.
· Carbon can bond with many more atomic species in a wider
variety of complex
· forms than other equivalent elements, such as silicon.
·
1 points
Question 7
· What do the letters SETI stand for? Answer
·
· 1.
· sourcebook of extrasensory transient incidents

·
· 2.
· search for extra-terrestrial intelligence
·
· 3.
· search for extra-terrestrial invaders
·
· 4.
· search for evidence of terrestrial-planet inhabitants
·
1 points
Question 8
· The Drake equation attempts to predict the Answer
·
· 1.
· number of intelligent civilizations that exist in the whole
universe.
·
· 2.
· number of technically advanced civilizations in the Milky Way
Galaxy.
·
· 3.
· probability of primitive life existing elsewhere in the Milky
Way Galaxy.
·
· 4.
· number of inhabitable planets around stars in the Milky Way
Galaxy.
·
1 points
Question 9
· Earth has been sending out radio messages for about 115
years, so detection equipment on a hypothetical planet 115
light-years away might just now begin receiving them. What is
the parallax angle subtended by a system at this distance? Can

we detect such a parallax angle with our present technology?
Answer
·
· 1.
· 0.028 arcseconds; yes
·
· 2.
· 0.0027 arcseconds; no
·
· 3.
· 115 arcseconds; yes
·
· 4.
· 0.0087 arcseconds; yes
·
1 points
Question 10
· Which object in the solar system seems to be the only one
capable of fostering an advanced civilization? Answer
·
· 1.
· Titan, a moon of Saturn
·
· 2.
· Earth
·
· 3.
· Callisto, a moon of Jupiter
·
· 4.
· Europa, a moon of Jupiter

Question 1·   What characteristic of Cepheid variables makes th.docx

Question 1·   What characteristic of Cepheid variables makes th.docx

Recommended

Recommended

More Related Content

Similar to Question 1·   What characteristic of Cepheid variables makes th.docx

Similar to Question 1·   What characteristic of Cepheid variables makes th.docx (20)

More from wraythallchan

More from wraythallchan (20)

Recently uploaded

Recently uploaded (20)