Final Exam
What is the approximate age of the star cluster in the HR diagram below? (Hint: Main Sequence Stars of spectral between types A and B core supply of hydrogen is sufficient to last about 250 million years. Between A and F about 2 billion years. Type G about 10 billion years. Between K and M about 30 billion years..)
Gledas kada linija od main sequence krene da menja normalni pravac (predje u desno); odgovor je starost poslednje zvezde pre nego sto je skenulo u desno
A black hole with a mass between 3 solar masses and 12 (it could be more than this though) solar masses is considered to be a Select one: a. stellar black hole b. dwarf black hole c. Kerr black hole d. primordial black hole e. supermassive black hole
a
A quasi-stellar radio source is now more commonly called a Select one: a. quasar b. neutron star c. magnetar d. pulsar e. supernova
a
A star with a mass of about 8 solar masses will Select one: a. be able to fuse carbon in the core b. collapse under the intense force of gravity until it forms a grey dwarf c. never be able to fuse helium d. use all of its fuel in about 10 million years and then explode
a
About how far can we see before intstellar dust begins to block our view of the stars? Select one: a. 1000 light years b. 550 light years c. 25 light years d. 100 light years e. 50,000 light years
a
After the main life of the sun, where it fuses hydrogen in the core, it will become a Select one: a. red gient b. red dwarf c. green dwarf d. blue giant
a
All of the following are layers within the sun EXCEPT Select one: a. conduction zone b. convection zone c. core d. radiative zone
a
All of the following are types of galaxies except Select one: a. Toroidal b. Spiral c. Irregular d. Peculiar e. Elliptical
a
Conservation of momentum is a law of physics that says that if a star is rotating before it collapses, then when it collapses it will Select one: a. rotate faster after the collapse b. continue rotating at the same rate c. stop rotating d. change its axis of rotation after the collapse e. rotate slower after the collapse
a
If Galaxy A is found to have a recessional velocity four times greater than Galaxy B, what can you say about their relative distances from Earth? Select one: a. Galaxy A is four times further away than Galaxy B. b. Galaxy A is four times closer than Galaxy B. c. Galaxy A is twice as distant than Galaxy B. d. Galaxy A is twice as close than Galaxy B.
a
Inside the core of a star, 4 protons (Hydrogen nuclei) join together to make Select one: a. one helium nucleus b. four helium nuclei c. one lithium nucleus d. two helium nuclei
a
Most of the mass of a galaxy is contained in the Select one: a. dark matter of the galaxy. b. disk of the galaxy. c. H I regions of the galaxy. d. H II regions of the galaxy. e. massive O and B stars in the galaxy.
a
One possible explanation for the weird, beautiful and fantastic shapes of planetary nebulae is that they Select one: a. swallowed some their planets which then stirred the interiors of the stars b. spun faster at first then slowed as material was ejected c. are affected somehow by the intense magnetic field of their star d. rotate faster at the equator than the poles, causing material to be flung away from the equator faster e. are caused by the precession of the axis of the star
a
Our sun will become a white dwarf with a mass of about half its original mass and a size of about Select one: a. 1/100 its original diameter b. 1/2 its original diameter c. 1/20 its original diameter d. 1/10 its original diameter e. 1/4 its original diameter
a
Planetary nebula typically glow for Select one: a. about 1000 years b. about a million years c. about 10 million years d. about 100 years e. about 100 million years
a
Population II stars I. are primarily found in the disk of the galaxy. II. contain more heavy metals than population I stars. III. are primarily old low mass stars. IV. are located in globular clusters. Select one: a. III & IV b. II c. I & II d. IV e. I, II, & III
a
Supermassive black holes are believed to be located at the center of many galaxies because Select one: a. the orbital motion of material near the center is very fast and indicates a very massive core. b. the spiral structure requires a black hole to maintain the spiral arms. c. the shape of the bulge in all spiral galaxies can only be supported by a supermassive black hole. d. the orbital speeds of a globular clusters in the galaxy are greater than the speed of light. e. the rotation curve of the galaxy indicates that 90% of the galaxy is dark matter.
a
The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on Select one: a. observations of globular clusters. b. the energy produced by Sagittarius A*. c. observations of open clusters. d. the rotation curve of the galaxy. e. 21-cm radiation from H I regions.
a
The escape velocity of the Earth is about 11 km/s. The sun has an escape velocity of 600 km/s. A neutron star can have an escape velocity of 150,000 km/s. What is the escape velocity at the event horizon of a black hole? Select one: a. 300,000 km/s (the speed of light) b. 150,000 km/s c. 450,000 km/s (1.5x the speed of light) d. 600,000 km/s (2x the speed of light) e. 200,000 km/s
a
The period-luminosity relation is useful in determining Select one: a. the distance to globular clusters that contain Cepheid variables. b. the mass of the Milky Way galaxy. c. the mass of a star for which the distance is known. d. the temperature of a star for which we know the luminosity. e. the radius of the bulge of our galaxy.
a
The supermassive black hole at the center of the Milky Way does not appear to be emitting light but is virtually invisible to us. This black hole without an accretion disk is called Select one: a. a quiescent black hole b. an infant black hole c. an active galaxy d. a mature black hole e. a naked black hole
a
This scientist was the first to declare that the universe was NOT static and unchanging, but either expanding or contracting. Select one: a. George Lemaitre b. Annie Cannon c. Albert Einstein d. Vesto Slipher e. Stephen Hawking
a
What is the universe expanding into? Select one: a. Nothing, it is creating spacetime as it expands b. A black hole c. Another universe d. The superuniverse e. The ether, which actually pervades all of spacetime as well
a
When a high mass star finishes fusing the hydrogen in the core and begins fusing helium in the core it will become a Select one: a. red supergiant b. blue supergiant c. blue giant d. red giant
a
When carbon fuses, it will produce all of the following EXCEPT Select one: a. aluminum (Al) b. sodium (Na) c. magnesium (Mg) d. neon (Ne)
a
When the sun begins fusing helium in its core, the process is highly unstable and Phil says the sun will go through a series of Select one: a. paroxysms b. supernovae c. unfortunate events d. reflexisms
a
Where would you find the Milkomeda Galaxy? Select one: a. It doesn't exist yet. It will be the galaxy that forms when the Milky Way and Andromeda Galaxies merge b. It is a satellite galaxy of the Andromeda Galaxy c. It is a member of the Leo Group d. It is a member of the Virgo Supercluster e. It is a member of the Ursa Major Group
a
Which of the following elements were created in the Big Bang? Select one: a. mostly hydrogen and helium (75% H and 25% He) b. only helium (100% He) c. only hydrogen (100% H) d. all the elements were created in their current abundance in the Big Bang e. The Big Bang was so hot that even after 380,000 years no elements could be created
a
White Dwarfs emit ultraviolet and even x-ray radiation, Select one: a. and have large magnitudes because they produce a lot of light b. but have low magnitudes because they do not produce a lot of light c. because they are relatively cool, similar to our sun d. and they are also the brightest gamma ray sources in the galaxy e. but curiously do not emit much visible light
a
A "low mass star" has a mass less than **(1 solar mass = mass of our Sun)** Select one: a. 1 solar mass b. 8 solar masses c. 0.33 solar masses d. 5 solar masses e. 0.5 solar masses
b
A magnetar has incredibly powerful magnetic fields. as much as a quadrillion times the magnetic field strength of our sun. Occasionally these will have star quakes, like earthquakes that can release energy in a flare a trillion times stronger than a typical solar flare. The amount of energy released in one of these events is the same as the sun releases in Select one: a. 50 year b. 250,000 years c. 1,000 years d. 250 years e. 2.5 Million years
b
A neutron star packs a mass of more than our sun into the size of Select one: a. the North American Continent b. a small city c. the planet Earth d. a basketball e. the state of Arizona
b
A planetary nebula is Select one: a. a cloud of hot gas surrounding a planet. b. the expelled outer envelope of a medium mass star. c. produced by a nova explosion. d. a nebula within which planets are forming. e. produced by a supernova explosion.
b
A(n) ____ emits large amounts of energy but photographically appears to be a single point of light much like a star. Select one: a. a planet like Venus b. quasar c. double-lobed radio galaxy d. E galaxy e. spiral galaxy
b
As a graduate student, Jocelyn Bell Burnell (and her advisor Antony Hewish who ultimately received a Nobel Prize for this work in 1974) is credited with the discovery of the first rapidly rotating neutron star, which she detected with a radio telescope array. The rapid rotation, together with the powerful magnetic field produces twin beams of energy whcih radiate away from the object. We call this a Select one: a. rotator b. pulsar c. spinor d. cosmic spinner e. hydrodynamic engine
b
As the high mass star fuses one fuel, the "ash" of the fusion reaction will accumulate in the core, and fusion in the core will stop. What happens to the core at that point? Select one: a. the core expands because of the fusion taking place outside the core b. the core shrinks and heats up until the ash is finally able to fuse c. the core material will begin to circulate and bring fresh fuel to the core d. the core shrinks and cools until the ash solidifies
b
As we observe more and more distant objects, the time the light takes to get to us is longer and longer. This means that we are seeing the object as it appeared in the past. The astronomical term for this is Select one: a. cosmological time b. lookback time Correct c. past time d. future time e. red shift time
b
Galactic cannibalism refers to Select one: a. binary galaxies. b. the merging of galaxies. c. galaxies drawing in gas from the intergalactic medium. d. the destruction of a galaxies globular clusters by the galaxies nucleus. e. none of these
b
In 1920, the Great Debate was an argument about whether the the Milky Way was the entire universe, or if the Milky Way was one of many similar type of objects. Who was the astronomer who argued that the Milky Way was all there is? Select one: a. Annie Cannon b. Harlow Shapley c. Edwin Hubble d. Subrahmanyan Chandrasekhar e. Heber Curtis
b
Massive stars cannot generate energy through iron fusion because Select one: a. iron fusion requires very high density. b. both fusion or fission of iron nuclei absorb energy c. no star can get hot enough for iron fusion. d. massive stars supernova before they create an iron core. e. stars contain very little iron.
b
The Big Bang must have been very hot, so hot that there would be a lot of visible light produced. Because of the expansion of the universe, this visible light has been red shifted to the ______________ range of the electromagnetic spectrum. Penzias and Wilson were awarded the Nobel prize in physics (1978) for their serendipitous discovery of this radiation in 1965. Select one: a. ultraviolet b. microwave c. x-ray d. red visible e. infrared
b
The Large Magellanic Cloud and Small Magellanic Cloud are considered _______________ of the Milky Way Galaxy. Select one: a. sibling galaxies b. satellite galaxies c. sire galaxies d. daughter galazies e. partner galaxies
b
The Milky Way Galaxy is a spiral galaxy with a disk shape whose dimensions are Select one: a. 100,000 light years across and 10 light years thick b. 100,000 light years across and several thousand light years thick c. 100,000 light years across and 50,000 light years thick d. 100,000 light years across and 100,000 light years thick e. 50,000 light years across and 100,000 light years thick
b
The Tarantula Nebula is forming so many stars that astronomers think it may be forming Select one: a. an open cluster b. a globular cluster c. a supermassive black hole d. a new galaxy
b
The gases expelled by a low mass star in its red giant phase don't get very far (about 1 light year or so) by the time the star collapses to form a white dwarf. When the radiation excites the gases, they glow and we call them a Select one: a. protostar b. planetary nebula c. black hole d. neutron star e. ionization cluster
b
The small cluster of galaxies that the Milky Way is a part of (a few dozen in all) is known as the Select one: a. Related Cluster b. Local Group c. Cluster Group d. Family Cluster e. Family Group
b
The study of the large scale structure of the universe is called Select one: a. cycadian astronomy b. cosmology c. grand astrology d. bangology e. cosmetology
b
These galaxies have odd or distorted shapes and are all due to collisions between galaxies that are still occuring. Select one: a. Elliptical b. Peculiar c. Irregular d. Toroidal e. Spiral
b
This force is what prevents a white dwarf from collapsing any further under the influence of gravity. Select one: a. neutron degeneracy pressure b. electron degeneracy pressure c. radiation pressure from the nuclear fission of carbon d. radiation pressure from nuclear fusion of helium e. proton degeneracy pressure
b
What is the Hubble constant essentially a measure of? Select one: a. The amount of dark matter in an average galaxy. b. The expansion of the universe. c. The age of the Milky Way galaxy. d. The number of galaxies in the universe.
b
What is the number of white dwarfs that have been found in our galaxy? Select one: a. only 1 has been found, about 9 light years from us called Sirius B b. over 10,000 c. slightly more than 100 d. over 1000 e. nearly 500
b
What will happen to the Earth when the sun becomes a black hole? Select one: a. it will get a little closer because the light from the sun will no longer be pushing on it b. Bad question. The sun will never be able to form a black hole c. It will continue to orbit the black hole at its current radius d. it will drift away from the sun due to the weakening of the gravitational field e. It will be sucked in because of the sun's increased gravitational field
b
When a neutron star is formed, this force is strong enough to oppose the incredibly strong force of gravity trying to collapse it further. Select one: a. electron degeneracy pressure b. neutron degeneracy pressure c. proton degeneracy pressure d. radiation pressure e. neutrino pressure
b
When ancient people looked up at the Milky Way, they saw a glow that looks like a nebula. Which of the following astronomers looked with a telescope and descovered that the Milky Way is made of countless stars, so close together that they could not be seen as separate with the naked eye. Select one: a. Edmond Halley b. Galileo Galilee c. William Herschel d. Edwin Hubble e. Christian Huygens
b
Which of the following can't be associated with the spiral arms of a galaxy? Select one: a. Dust and gas b. Metal poor stars c. Young, massive stars d. Star formation
b
Which of the following statements is true about high mass stars Select one: a. They have a higher mass, but fuse at about the same rate as lower mass stars so they have longer lives. b. They have a higher mass, but fuse at much higher rate than lower mass stars so they have shorter lives. c. They have a higher mass, and fuse at a higher rate as lower mass stars but they still live longer. d. They have a higher mass, but fuse at slower rate than lower mass stars so they have longer lives.
b
With higher pressure, the nuclear fusion process occurs more frequently, releasing more energy. The lower the mass of a star, the Select one: a. more energy will be released by fusion in the core b. longer its life will be c. hotter its core will be d. greater the pressure will be in the core e. shorter its life will be
b
a. The center of mass of the Local Group of galaxies b. Every point in the universe looks like the center, so no point is actually the center of the universe c. The Virgo supercluster of galaxies d. The center is approximately 35,000,000 LY from us in the direction of the constellation Cameleopardis. e. The supermassive black hole at the center of the Milky Way galaxy
b
A Type I supernova is believed to occur when Select one: a. hydrogen detonation occurs. b. the cores of massive stars collapse. c. a white dwarf exceeds the Chandrasekhar limit. d. the core of a massive star collapses. e. neutrinos in a massive star become degenerate and form a shock wave that explodes the star.
c
A really low mass red dwarf can live as long as Select one: a. a billion years b. 100 billion years c. a trillion years d. 5 billion years e. 10 billion years
c
A spiral galaxy can grow by Select one: a. fling some stars awy from the center and some stars toward the center of the galaxy b. supernovae converting hydrogen into heavier elements c. absorbing smaller galaxies d. making more stars
c
A star with a mass between 8 and 20 solar masses will undergo nuclear fusion in the core all the way up to iron (Fe) before exploding in a supernova explosion. If the remaining core mass is more than 1.4 solar masses and less than 2.8 solar masses then this incredibly dense object will form. Select one: a. an electron star b. a white dwarf c. a neutron star d. a proton star e. a black hole
c
About how long will a 0.5 star spend on the main sequence? Select one: a. 5 million years b. 5 billion years c. 57 billion years d. 570 million years e. 500 thousand years
c
According to Einstein's theory of general relativity, the force that we perceive to be gravity is really just the warping of the fabric of spacetime. The presence of mass causes this fabric to be warped and the larger the mass, the more it warps spacetime. The strange thing is that time will not pass the same for people in different gravitational fields, according to an outside observer. The greater the warping of spacetime (the stronger the gravitational field) Select one: a. the faster the clocks will appear to tick b. does not matter; clocks will always tick in the same way c. the slower the clocks will appear to tick
c
According to Phil, our solar system is located Select one: a. near the center of the Milky Way b. about 3/4 of the way from the center to the edge of the Milk Way c. about 1/2 of the way from the center to the edge of the Milk Way d. about 1/4 of the way from the center to the edge of the Milk Way e. at the outer rim of the Milky Way
c
Because they are incredibly dense objects, 1 cubic centimeter of a white dwarf mass (about the size of a six-sided die) is about Select one: a. 100 million grams (one hundred metric tons) b. a billion grams (one thousand metric tons) c. a million grams (one metric ton) d. 100 kg (0.1 metric tons) e. a million tons
c
Clusters of galaxies clump together to form larger structures known as ________________ which are held together by their mutual gravitational attraction. Select one: a. Galaxy spheres b. Supergroups c. Superclusters d. Galaxy neighborhoods e. Gravitational webs
c
Gravitational lensing Select one: a. can be used to determine the luminosity of a galaxy. b. can be used to determine the recessional velocity of a galaxy. c. occurs when light passes near a massive object and is deflected by the object's gravitational field. d. occurs when the mass of a galaxy is less than expected from the luminosity of the galaxy. e. occurs when the mass of a galaxy is greater than expected from the luminosity of the galaxy.
c
If a star has less than 20 Solar Masses when it collapses, then it will form a compact object about 20 km in diameter called a __________________ with part of the matter, and the rest of the matter will explode outward in a Type II supernova. Select one: a. black hole b. brown dwarf c. neutron star d. white dwarf e. red giant
c
If the theory that novae occur in close binary systems is correct, then novae should Select one: a. produce synchrotron radiation. b. not occur in old star clusters. c. repeat after some interval. d. occur in regions of star formation. e. all be visual binaries.
c
If you were to fall feet first into a 10 solar mass black hole, the tidal forces would Select one: a. flatten you like a piece of paper b. affect your head more than your feet c. spaghettify you d. compress you into a tiny sphere e. squeeze you like a lemon
c
Instead of releasing energy, the fusion of _________________ absorbs energy and causes the core to collapse completely. Select one: a. oxygen (O) b. carbon (C) c. iron (Fe) d. silicon (Si) e. argon (Ar)
c
Lower mass stars cannot ever achieve a high enough temperature and pressure to ignite Carbon fusion. What is the temperature needed to fuse carbon in a star core? Select one: a. 200,000,000K b. 10,000,000K c. 500,000,000K d. 1,000,000K e. 100,000,000K
c
Measuring the Doppler shift of radio waves emitted in a narrow band by young star-forming regions allowed us to "see" that the Milky Way Select one: a. is made of metal-rich stars b. is very dusty c. has spiral arms d. is collapsing e. is expanding
c
Most of the elements on the periodic table are produced by the expanding shockwave from a type II supernova. This process is known as Select one: a. nuclear fission b. stellar nucleosynthesis c. explosive (supernova) nucleosynthesis d. nuclear fusion
c
Most of the globular clusters in the Milky Way are found in Select one: a. the galactic disk b. the Andromeda Galaxy c. the galactic halo d. the galactic bar or bulge e. a ring around the edge of the Milky Way
c
Much of the red color in planetary nebulae comes from hydrogen. The green color in nebulae was originally thought to come from an unknown element, named Nebullium, but in the end it turns out it comes from ordinary Select one: a. nitrogen (N) b. carbon (C) c. oxygen (O) d. mercury (Hg) e. neon (Ne)
c
The Greek word Galaxius means Select one: a. Humongous b. Huge river c. Milky d. Broad river e. Clean
c
The chemical abundance of population I stars Select one: a. indicates that they were formed before the population II stars. b. indicates that they contain very few heavy metals compared to halo stars. c. indicates that the material they formed from had been enriched with material from supernovae. d. depends on the mass of the star. e. depends on the temperature of the star.
c
The energy from an AGN is produced by Select one: a. the collision of two radio jets. b. the collision of two elliptical galaxies. c. matter flowing into a supermassive black hole. d. supernovae. e. the collision of two spiral galaxies.
c
The explosion of a supernova typically leaves behind Select one: a. a shell of hot, expanding gas with a white dwarf at the center. b. a planetary nebula. c. a shell of hot, expanding gas with a pulsar at the center. d. nothing is ever left behind.
c
The largest known star is 2 Billion km in diameter, and is known as a hypergiant. What is the name of the largest known star? Select one: a. Betelgeuse b. Rigel c. VY Canis Majoris d. Arcturus e. Antares
c
The sun will never be able to fuse carbon in the core so the force of gravity will compress it into a sphere the size of the Earth called a Select one: a. neutron star b. red dwarf c. white dwarf d. brown dwarf
c
The surface temperature of a newly formed white dwarf can be about Select one: a. 1,000,000 K b. 6,000 K c. 100,000 K d. 10,000,000 K e. 10,000 K
c
What do astronomers now think powers active galaxies? Select one: a. binary red supergiant stars b. stellar mass black holes c. supermassive black holes d. binary neutron stars e. co-orbiting neutron stars
c
When light escapes from a black hole, it appears to lose energy. This is known as Select one: a. Doppler blueshift b. Doppler redshift c. Gravitational redshift d. Gravitational blueshift e. conservation of energy
c
Where are elements heavier than iron primarily produced? Select one: a. Brown dwarfs b. White dwarfs c. Supernovae d. Supergiants
c
Which of the following is the largest object? Select one: a. The Andromeda galaxy. b. The Large Magellanic Cloud. c. The Local Group. d. The Milky Way galaxy.
c
Younger stars have more heavy elements because Select one: a. old stars destroy heavy elements as they age. b. young stars burn their nuclear fuels faster. c. the heavy elements were made in previous generations of stars. d. heavy elements haven't had time to settle to the core of these younger stars. e. all of these
c
____ of the Milky Way contains mostly old (population II) stars and globular clusters. Select one: a. The hydrogen gas in the disk b. The disk component c. The spherical halo component d. The spiral arms e. Sgr A*
c
___________ can be used to determine the galaxy's mass if the galaxy is reasonably close so that the Doppler shift of the galaxy disk material can be measured at several distances from the galaxy's center relative to the center. Select one: a. A galaxy's diameter b. A galaxy's color c. A galaxy's rotation curve d. The Hubble constant e. The velocity dispersion method
c
A group of 10 to 100 stars that formed at the same time but are so widely scattered in space their mutual gravity cannot hold them together is called Select one: a. a globular cluster. b. an open cluster. c. an accretion disk. d. an association. e. a spherical component
d
A star with 8 Solar Masses will fuse hydrogen for Select one: a. about 10 Million Years b. about 1 Million Years c. about 1 Billion Years d. about 100 Million Years e. about 5 Billion Years
d
According to Phil, when compared to lower mass stars, higher mass stars go out Select one: a. silently b. with a whisper c. with an explosion d. with a bang e. with a whimper
d
Edwin Hubble and (partner) carefully studied the galaxies that had been studied by Slipher and concluded that the further away a galaxy was from us, Select one: a. the slower it was receding from us. b. the more likely it was to not be moving relative to us. c. the more likely it was to be made of younger, metal rich stars. d. the faster it was receding from us. e. the more likely it was to be made up of larger mass stars.
d
How does the traditional theory of the formation of the galaxy explain the origin of globular clusters? Select one: a. They build over time from the collision of stars in the halo. b. They formed in other galaxies and were captured by close interactions. c. They formed in the disk and later were ejected to the halo. d. They formed early on during the free-fall collapse of the proto-galactic material.
d
How is the age of the galaxy determined? Select one: a. Measuring the metallicity of Population II stars. b. From the motion of stars in the galactic halo. c. Counting the number of open clusters in the spiral arms. d. Finding the turnoff point in the H-R diagram of globular clusters.
d
If a supernova remnant core has a mass greater than 2.8 solar masses, then what force will be able to stop gravity from collapsing the core? Select one: a. radiation pressure b. neutrino degeneracy pressure c. electron degeneracy pressure d. nothing; it is not possible to stop gravity in this case e. neutron degeneracy pressure
d
If you could magnify an atom to be 100 meters across (the size of a football field), then the nucleus would be about the size of Select one: a. a grain of sand b. a baseball c. a basketball d. a marble e. a football
d
In March 2011, a star which wandered in too close to a black hole was Select one: a. swallowed up in one quick gulp b. completely unaffected by the black hole c. pulled apart to make two smaller stars which now orbit the black hole d. completely ripped apart and briefly flared to be as bright as a trillion suns e. flung out of its ogalaxy into intergalactic space
d
Pulsating stars, that change their brightness with a regular period are known as ____________. They were important for determining the distance to galaxies because their period is related to their luminosity (L). Select one: a. pulsars b. neutron stars c. supernovae d. Cepheid variables. e. novae
d
The Crab nebula is Select one: a. a Bok globule. b. a planetary nebula. c. an open cluster. d. supernova remnant. e. an absorption nebula.
d
The Hubble Law is a relation between a galaxy's Select one: a. mass and its luminosity. b. mass and its recession velocity. c. distance and its luminosity. d. distance and its recession velocity. e. mass and its diameter.
d
The Milky Way galaxy is part of Select one: a. the Virgo cluster. b. the Large Magellanic Cloud. c. a rich cluster. d. the Local Group. e. the Small Magellanic Cloud.
d
The density of neutron stars matter, neutronium, is about 400 million metric tons per cubic inch. Phil tells us this is like squishing _________________ into one single six-sided die. Select one: a. all of the automobiles in China b. all of the water on Earth c. all of the people on Earth d. all of the automobiles in North America e. all of the automobiles on the entire Earth
d
The theory that the collapse of a massive star's iron core produces neutrinos was supported by Select one: a. the brightening of supernovae a few days after they are first visible b. the size and structure of the Crab nebula. c. laboratory measurements of the mass of the neutrino. d. the detection of neutrinos from the supernova of 1987. e. underground counts from solar neutrinos.
d
What distance method is used to determine the distance to the most distant galaxies? Select one: a. Period-luminosity relationship of variable stars b. Parallax c. Radar echo d. Supernova observations
d
What nuclear fusion mechanism does an isolated white dwarf use to generate energy? Select one: a. Triple alpha process b. CNO cycle c. Proton-proton chain d. White dwarfs don't generate their own energy.
d
When the hydrogen in our sun's core runs out, it will begin to collapse and heat up. What will happen in the shell around the core as a result? Select one: a. It will contract as well and heat up more b. It will turn to liquid under the extreme pressures c. It will get hot enough to fuse helium d. It will get hot enough to fuse hydrogen
d
Which of the following nuclear fuels does a one solar mass star use over the course of its entire evolution? Select one: a. hydrogen, helium, carbon, and neon b. hydrogen, helium and carbon c. hydrogen d. hydrogen and helium e. hydrogen, helium, carbon, neon, and oxygen.
d
____ is a form of electromagnetic radiation produced by rapidly moving electrons spiraling through magnetic fields. Select one: a. Ultraviolet radiation b. Lagrangian radiation c. Infrared radiation d. Synchrotron radiation e. Accretion
d
A "high mass" star is a star which begins with Select one: a. more than 3 Solar Masses b. about 5 Solar Masses c. more than 12 Solar Masses d. about 6 Solar Masses e. more than 8 Solar Masses
e
A mega-parsec is equivalent to Select one: a. the age of our solar system b. the diameter of the Milky Way galaxy. c. 3.26 light-years. d. 206,265 AU e. a million parsecs.
e
A region near a black hole has matter orbiting the black hole at nearly the speed of light and is heated from friction and other interactions. This region is reaches temperatures of millions of degrees and consequently emits a huge amount of light across the spectrum. Select one: a. singularity b. photosphere c. halo region d. event horizon e. accretion disk
e
Active galaxies are notable because they are point sources that emit extremely energetic streams of Select one: a. gamma ray photons b. x-ray photons c. infrared photons d. visible light photons e. Either a. or b.
e
At the center of the Milky Way Galaxy is a supermassive black hole with a mass of Select one: a. 10 Million Solar Masses b. 2.2 Million Solar Masses c. 2.5 Million Solar Masses d. 2.75 Million Solar Masses e. 4 Million Solar Masses
e
At the core of nearly every galaxy is higher mass black hole. The first one that was conclusively observed is the one at the center of the Milky Way with a mass of more than 4 million solar masses. These black holes at the centers of glaxies are known as Select one: a. stellar black hole b. Kerr black hole c. dwarf black hole d. primordial black hole e. supermassive black hole
e
For a short while, astronomers were unsure of the source of regular radio pulses from space and gave them the name LGMs. What does LGM stand for? Select one: a. Light Generated Minutia b. Lower Generation Manifestation c. Light Guided Missiles d. Laser Green Medallions e. Little Green Men
e
If we reverse the expansion of the universe and ask when all of the material in the universe was in the same location, the age of the universe can be determined. According to Phil the current, best estimate for the age of the universe is (the value has been updated slightly since the video was recorded but is close to this value) Select one: a. 46.75 Billion years b. 4.76 Billion years c. 10.21 Billion years d. 11.05 Billion Years e. 13.82 Billion years
e
In the 1960s the object known as 3C273 appeared with optical telescopes to be a dim blue object, but extremely bright in the radio part of the spectrum. It was determined from its spectra to be a Select one: a. a cool, but relatively close star cluster b. normal blue star c. a pulsar with a red giant companion about 50 light years away d. a supernova remanant about 150,000 light years away e. an entire galaxy more than 2 billion light years away
e
It wont happen on its own, but in order to form a black hole with a star the mass of our sun, it would need to be compressed to a diameter of only Select one: a. 50 km b. 20 km c. 60 km d. 100 km e. 6 km
e
Our sun is thought to be on a small projection from one of the major arms of the Milky Way Galaxy, called the Select one: a. Persueus Arm b. Norma Arm c. Sagittarius Arm d. Outer Arm e. Orion Arm
e
Stars in a star cluster Select one: a. all have the same age. b. all have the same chemical composition. c. all have the same luminosity. d. all of the above e. a and b above
e
The Chandrasekhar limit tells us that Select one: a. stars cannot travel through space too fast b. neutron stars of more than 3 solar masses are not stable. c. stars with a mass less than 0.5 solar masses will not go through helium flash. d. accretion disks can grow hot through friction. e. white dwarfs more massive than 1.4 solar masses are not stable.
e
The Hubble "Deep Field" image was taken in the 1990s of one of the darkest areas of the sky. It observed a small spot of the sky about 2.6 arcminutes on a side (about the size of a grain of sand held in your hand at arm's length) and took a picture over the course of ten days. When the picture was analyzed they found Select one: a. it was full of glowing dust b. it contained hundreds of stars c. it was mostly empty space d. it countained millions of stars e. it contained thousands of galaxies
e
The astronomer named Vesto Slipher who according to Phil has the "uncontested, coolest name for an astronomer", began in 1912 abserving the spectra of spiral galaxies and by 1917 had observed 25 of them. What was the remarkable discovery that he made? Select one: a. The galaxies showed very little metal in their spectra indicating that they are made of Population II stars. b. The galaxies were highly blue shifted indicating the galaxies were rapidly approaching our galaxy. c. The galaxies had supermassive black holes at their centers emitting x-rays. d. The galaxies had masses from 10-100 times the mass of the Milky Way galaxy. e. The galaxies were highly red shifted indicating the galaxies were rapidly moving away from our galaxy.
e
The look-back time is Select one: a. the time it takes for the light from an object to reach Earth. b. numerically equal to the distance in light-years. c. smaller for more distant objects. d. all of the above e. a and b above
e
The orbits of population I stars I. are confined to disk of the galaxy. II. are very elliptical. III. are nearly circular. IV. are randomly inclined to the disk of the galaxy. Select one: a. I b. IV c. I & IV d. II & IV e. I & III
e
The reason a low mass star can live so long is that Select one: a. it fuses its hydrogen fuel more slowly b. the fusion takes place throughout the star c. the region outside the core is convective so the fuel can make it back to the core where it will eventually be used d. it gets new fuel from neighboring stars e. Both a. and c. are true
e
The region surrounding the Milky Way out to about 100,000 light years is made up of old, stable red dwarf stars and NO star-forming regions is called Select one: a. the stellar graveyard b. the bowl c. the stellar nursery d. the hat e. the halo
e
These galaxies are characterized by a lack of gas and dust and are primarily made of older stars. They range in size from a few thousand light years across to vastly larger than the Milky Way. Select one: a. Irregular b. Spiral c. Peculiar d. Toroidal e. Elliptical
e
Two huge, looping streams of stars circling the Milky Way are probably part of the Sagittarius and Canis Majoris galaxies Select one: a. were ripped apart by the Andromeda Galaxy before orbiting the Milky Way b. pulling material out of the Milky Way c. passing by like a comet past our solar system d. and will merge to form a "moon" or daughter galaxy around the Milky Way e. being eaten by the Milky Way
e
What happens when protons and electrons are pushed together under extreme pressures? Select one: a. they form a positron electron pair plus two neutrinos b. they annihilate each other and release light energy c. they merge and form a negatively charged neutron d. they form a positively charged prion e. they merge and form a neutral neutron
e
When galaxies collide, what is the most likely outcome? Select one: a. The galaxies will orbit each other for several billion years before separating and continuing on their original paths b. The stars and the gas clouds can pass of one galaxy can pass right through the stars and dust clouds of the other galaxy so no collision is likely to occur c. One will be ripped apart by tidal forces and the other will become more compact d. The smaller galasy will grow while the larger galaxy will shrink until they have approximately the same mass e. They will eventually merge to form a single galaxy
e
When the sun is a red giant, what will happen to the Earth? Select one: a. the Earth will freeze because the surface of the sun is cooler b. the Earth will become a molten ball much like when it was formed c. the Earth will fall into the sun because the force of gravity will increase d. the Earth may move out to a larger radius because the sun will exert a weaker force of gravity e. Both b. and d. are correct
e
In the diagram below, which point indicates the location on the HR diagram of a one solar mass star when it undergoes helium flash?
predje u Red Giant fazu; iznad main sequence (5)