Astronomy Final Quizzes
Supernova is as bright 4 to 10 billion suns and emits the energy of 300 years of sunlight in ______.
1 second
2 nuclear processes: ____ and ____ nucleosynthesis.
1. Stellar Nucleosynthesis s-process (s=slow) Some of the heavier elements are formed 2. Supernova Nucleosynthesis r-process (r=rapid). ALL of the other elements are formed in their correct abundances
Types of galaxies
1. elliptical galaxies: largest & smallest, almost no dust/gas 2. disk shaped galaxies: spiral arms, dust/gas in arms 3. Irregulars: no overall structure, rich in dust/gas
A neutron star is the size of a small city, a spoonful would be __________.
100 of millions of tons.
Guest star was seen for ________.
23 days in the daytime, 2 years at night.
Synchotron radiation
Electrons spiralling in a magnetic field Increase speed = higher frequency (energy) Synchrotron radiation is polarized
Who coined the Big Bang theory?
George Gamow
Crab Nebula
I. expansion rate of 900 mi/sec II. distance = 6,000 LY III. D = 6 LY IV. started to expand 900 years ago
Length Contraction
Length Contraction • As objects move through spacetime, space as well as time changes. • Space is contracted, making the objects look shorter when they move by us at relativistic speeds. (only takes place in the direction of travel)
Frame of reference
The place from which motion is observed and measured is a frame of reference. - An object may have different velocities relative to different frames of reference.
Cosmic rays
Very high speeds, mostly isolated protons, nuclei of H, He, C, Se, and Fe. Seem to come from everywhere; Zwicky proposed they came from supernovas.
Neutron degeneracy is __________.
When matter is crushed to the point where electron are driven into protons leaving only neutrons which can be compressed no further
If, after a supernova, the stellar core retains less than 3 solar masses, the result will most likely be ____________.
a neutron star
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. 1/10 its original diameter d. 1/20 its original diameter e. 1/4 its original diameter
a. 1/100 its original diameter
The surface temperature of a newly formed white dwarf can be about Select one: a. 100,000 K b. 10,000,000 K c. 10,000 K d. 6,000 K e. 1,000,000 K
a. 100,000 K
The Milky Way Galaxy is a spiral galaxy with a disk shape whose dimensions are Select one: a. 100,000 light years across and several thousand light years thick b. 100,000 light years across and 100,000 light years thick c. 50,000 light years across and 100,000 light years thick d. 100,000 light years across and 10 light years thick e. 100,000 light years across and 50,000 light years thick
a. 100,000 light years across and several thousand light years thick
How is the age of the galaxy determined? Select one: a. Finding the turnoff point in the H-R diagram of globular clusters. b. From the motion of stars in the galactic halo. c. Measuring the metallicity of Population II stars. d. Counting the number of open clusters in the spiral arms.
a. Finding the turnoff point in the H-R diagram of globular clusters.
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. Vesto Slipher c. Albert Einstein d. Stephen Hawking e. Annie Cannon
a. George Lemaitre
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. Harlow Shapley b. Subrahmanyan Chandrasekhar c. Edwin Hubble d. Heber Curtis e. Annie Cannon
a. Harlow Shapley
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. Orion Arm b. Outer Arm c. Sagittarius Arm d. Norma Arm e. Persueus Arm
a. Orion Arm
Where are elements heavier than iron primarily produced? Select one: a. Supernovae b. White dwarfs c. Brown dwarfs d. Supergiants
a. Supernovae
The astronomer named Vesto Slipher began in 1912 observing 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 were highly red shifted indicating the galaxies were rapidly moving away from our galaxy. b. The galaxies showed very little metal in their spectra indicating that they are made of Population II stars. 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 blue shifted indicating the galaxies were rapidly approaching our galaxy.
a. The galaxies were highly red shifted indicating the galaxies were rapidly moving away from our galaxy.
How does the traditional theory of the formation of the galaxy explain the origin of globular clusters? Select one: a. They formed early on during the free-fall collapse of the proto-galactic material. b. They formed in the disk and later were ejected to the halo. c. They formed in other galaxies and were captured by close interactions. d. They build over time from the collision of stars in the halo.
a. They formed early on during the free-fall collapse of the proto-galactic material.
What nuclear fusion mechanism does an isolated white dwarf use to generate energy? Select one: a. White dwarfs don't generate their own energy. b. CNO cycle c. Proton-proton chain d. Triple alpha process
a. White dwarfs don't generate their own energy.
A neutron star packs a mass of more than our sun into the size of Select one: a. a small city b. the state of Arizona c. the planet Earth d. the North American Continent e. a basketball
a. a small city
A spiral galaxy can grow by Select one: a. absorbing smaller galaxies b. supernovae converting hydrogen into heavier elements c. making more stars d. fling some stars awy from the center and some stars toward the center of the galaxy
a. absorbing smaller galaxies
White Dwarfs emit ultraviolet and even x-ray radiation, Select one: a. but have low luminosity because they do not produce a lot of light b. and they are also the brightest gamma ray sources in the galaxy c. because they are relatively cool, similar to our sun d. and have large magnitudes because they produce a lot of light e. but curiously do not emit much visible light
a. but have low luminosity because they do not produce a lot of light
A white dwarf is composed of a. carbon and oxygen nuclei and degenerate electrons b. a helium burning core and a hydrogen burning shell c. helium nuclei and normal electrons d. degenerate iron nuclei e. hydrogen nuclei and degenerate electrons
a. carbon and oxygen nuclei and degenerate electrons A white dwarf is small, dense, no longer fusing, a remnant of a red giant's carbon core; 0.8 Solar Masses aka the smallest mass to be a star; a star can be as big as 8 solar masses and still become a white dwarf. Chandrashekar limit.
In March 2011, a star which wandered in too close to a black hole was Select one: a. completely ripped apart and briefly flared to be as bright as a trillion suns b. pulled apart to make two smaller stars which now orbit the black hole c. flung out of its ogalaxy into intergalactic space d. swallowed up in one quick gulp e. completely unaffected by the black hole
a. completely ripped apart and briefly flared to be as bright as a trillion suns
Most of the mass of a galaxy is contained in the Select one: a. dark matter of the galaxy. b. H I regions of the galaxy. c. disk of the galaxy. d. massive O and B stars in the galaxy. e. H II regions of the galaxy.
a. dark matter of the galaxy.
The energy from an AGN is produced by Select one: a. matter flowing into a supermassive black hole. b. the collision of two radio jets. c. the collision of two elliptical galaxies. d. supernovae. e. the collision of two spiral galaxies.
a. matter flowing into a supermassive black hole.
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. nothing; it is not possible to stop gravity in this case b. neutrino degeneracy pressure c. electron degeneracy pressure d. radiation pressure e. neutron degeneracy pressure
a. nothing; it is not possible to stop gravity in this case
Gravitational lensing Select one: a. occurs when light passes near a massive object and is deflected by the object's gravitational field. b. occurs when the mass of a galaxy is less than expected from the luminosity of the galaxy. c. occurs when the mass of a galaxy is greater than expected from the luminosity of the galaxy. d. can be used to determine the luminosity of a galaxy. e. can be used to determine the recessional velocity of a galaxy.
a. occurs when light passes near a massive object and is deflected by the object's gravitational field.
What is the number of white dwarfs that have been found in our galaxy? Select one: a. over 10,000 b. over 1000 c. nearly 500 d. slightly more than 100 e. only 1 has been found, about 9 light years from us called Sirius B
a. over 10,000
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. oxygen (O) b. neon (Ne) c. carbon (C) d. nitrogen (N) e. mercury (Hg)
a. oxygen (O)
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 galaxies are known as Select one: a. supermassive black hole b. Kerr black hole c. stellar black hole d. primordial black hole
a. supermassive black hole
The Milky Way galaxy is part of Select one: a. the Local Group. b. the Virgo cluster. c. a rich cluster. d. the Small Magellanic Cloud. e. the Large Magellanic Cloud.
a. the Local Group.
The theory that the collapse of a massive star's iron core produces neutrinos was supported by Select one: a. the detection of neutrinos from the supernova of 1987. b. underground counts from solar neutrinos. c. laboratory measurements of the mass of the neutrino. d. the size and structure of the Crab nebula. e. the brightening of supernovae a few days after they are first visible.
a. the detection of neutrinos from the supernova of 1987.
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 faster it was receding from us. b. the slower it was receding from us. c. the more likely it was to be made up of larger mass stars. d. the more likely it was to be made of younger, metal rich stars. e. the more likely it was to not be moving relative to us.
a. the faster it was receding from us.
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 orbital speeds of a globular clusters in the galaxy are greater than the speed of light. c. the spiral structure requires a black hole to maintain the spiral arms. d. the rotation curve of the galaxy indicates that 90% of the galaxy is dark matter. e. the shape of the bulge in all spiral galaxies can only be supported by a supermassive black hole.
a. the orbital motion of material near the center is very fast and indicates a very massive core.
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 slower the clocks will appear to tick b. does not matter; clocks will always tick in the same way c. the faster the clocks will appear to tick
a. the slower the clocks will appear to tick
The Chandrasekhar limit tells us that Select one: a. white dwarfs more massive than 1.4 solar masses are not stable. b. accretion disks can grow hot through friction. c. neutron stars of more than 3 solar masses are not stable. d. stars cannot travel through space too fast e. stars with a mass less than 0.5 solar masses will not go through helium flash.
a. white dwarfs more massive than 1.4 solar masses are not stable.
White dwarfs are about _____ tons per teaspoon. a. 100 b. 10 c. 1,000 d. 10,000
b. 10
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. 200,000 km/s b. 300,000 km/s (the speed of light) c. 600,000 km/s (2x the speed of light) d. 150,000 km/s e. 450,000 km/s (1.5x the speed of light)
b. 300,000 km/s (the speed of light)
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. 20 km b. 6 km c. 50 km d. 100 km e. 60 km
b. 6 km
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. Peculiar b. Elliptical c. Spiral d. Toroidal e. Irregular
b. Elliptical
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 twice as distant than Galaxy B. b. Galaxy A is four times further away than Galaxy B. c. Galaxy A is twice as close than Galaxy B. d. Galaxy A is four times closer than Galaxy B.
b. Galaxy A is four times further away than Galaxy B.
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. Laser Green Medallions b. Little Green Men c. Lower Generation Manifestation d. Light Generated Minutia e. Light Guided Missiles
b. Little Green Men
Which of the following can't be associated with the spiral arms of a galaxy? Select one: a. Young, massive stars b. Metal poor stars c. Dust and gas d. Star formation
b. Metal poor stars
The Greek word Galaxius means Select one: a. Huge river b. Milky c. Broad river d. Humongous e. Clean
b. Milky
What is the universe expanding into? Select one: a. A black hole b. Nothing, it is creating spacetime as it expands c. The superuniverse d. Another universe e. The ether, which actually pervades all of spacetime as well
b. Nothing, it is creating spacetime as it expands
____ is absorbed by ozone in Earth's atmosphere that is located between 20km and 40km above Earth's surface. Telescopes and cameras that can observe this radiation must be placed in space a. X-ray radiation b. Ultraviolet radiation c. Infrared radiation d. Visible light e. Radio wave radiation
b. Ultraviolet radiation
The Tarantula Nebula is forming so many stars that astronomers think it may be forming Select one: a. a supermassive black hole b. a globular cluster c. an open cluster d. a new galaxy
b. a globular cluster
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 automobiles in North America c. all of the automobiles on the entire Earth d. all of the people on Earth e. all of the water on Earth
b. all of the automobiles in North America
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 supernova remanant about 150,000 light years away b. an entire galaxy more than 2 billion light years away c. normal blue star d. a pulsar with a red giant companion about 50 light years away e. a cool, but relatively close star cluster
b. an entire galaxy more than 2 billion light years away
Two huge, looping streams of stars circling the Milky Way are probably part of the Sagittarius and Canis Majoris galaxies Select one: a. passing by like a comet past our solar system b. being eaten by the Milky Way c. were ripped apart by the Andromeda Galaxy before orbiting the Milky Way d. pulling material out of the Milky Way e. and will merge to form a "moon" or daughter galaxy around the Milky Way
b. being eaten by the Milky Way
The study of the large scale structure of the universe is called Select one: a. grand astrology b. cosmology c. cycadian astronomy d. bangology e. cosmetology
b. cosmology
The event horizon of a black hole is a mathematical place where the escape velocity is a. smaller than the speed of light b. equal to the speed of light c. much larger than the speed of light d. undefined because nothing (including light) can escape from a black hole e. equal to the speed of sound
b. equal to the speed of light
Which of the following nuclear fuels does a one solar mass star use over the course of its entire evolution? Select one: a. hydrogen b. hydrogen and helium c. hydrogen, helium, carbon, neon, and oxygen. d. hydrogen, helium and carbon e. hydrogen, helium, carbon, and neon
b. hydrogen and helium
The chemical abundance of population I stars Select one: a. indicates that they contain very few heavy metals compared to halo stars. b. indicates that the material they formed from had been enriched with material from supernovae. c. depends on the mass of the star. d. depends on the temperature of the star. e. indicates that they were formed before the population II stars.
b. indicates that the material they formed from had been enriched with material from supernovae.
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 contained hundreds of stars b. it contained thousands of galaxies c. it countained millions of stars d. it was mostly empty space e. it was full of glowing dust
b. it contained thousands of galaxies
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. red shift time b. lookback time c. past time d. cosmological time e. future time
b. lookback time
Which of the following elements were created in the Big Bang? Select one: a. only helium (100% He) b. mostly hydrogen and helium (75% H and 25% He) c. all the elements were created in their current abundance in the Big Bang d. only hydrogen (100% H) e. The Big Bang was so hot that even after 380,000 years no elements could be created
b. mostly hydrogen and helium (75% H and 25% He)
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. ionization cluster b. planetary nebula c. neutron star d. black hole e. protostar
b. planetary nebula
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. change its axis of rotation after the collapse b. rotate faster after the collapse c. continue rotating at the same rate d. rotate slower after the collapse e. stop rotating
b. rotate faster after the collapse
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. partner galaxies e. daughter galazies
b. satellite galaxies
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. primordial black hole b. stellar black hole c. dwarf black hole d. supermassive black hole e. Kerr black hole
b. stellar black hole
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. the merging of galaxies.
If you compare two stars a. the one with the larger surface area has the greater energy flux from its surface b. the one with the lower absolute magnitude will always have the greater luminosity c. the one with the larger radius will always have the greater luminosity d. the one with the higher surface temperature will always have the greater luminosity
b. the one with the lower absolute magnitude will always have the greater luminosity (H-R Diagram; the vertical line is absolute magnitude/luminosity) A star spends 90% of it's life on the Main Sequence because it's burning hydrogen in the core. Our sun is a G-1 with an absolute magnitude of +5)
The central regions of Earth's core (different layers because of differentiation) are solid because a. the composition at the center of the core is lower in iron b. the pressure at the center raises the melting point c. the magnetic field cannot penetrate into the center of the core d. convection does not extend all the way to the center of the core e. Earth initially formed from solid particles in the solar nebula
b. the pressure at the center raises the melting point (6,000K)
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. 2.75 Million Solar Masses c. 4 Million Solar Masses d. 2.2 Million Solar Masses e. 2.5 Million Solar Masses
c. 4 Million Solar Masses
When light escapes from a black hole, it appears to lose energy. This is known as Select one: a. Gravitational blueshift b. conservation of energy c. Gravitational redshift d. Doppler redshift e. Doppler blueshift
c. Gravitational redshift
Where would you find the Milkomeda Galaxy? Select one: a. It is a member of the Ursa Major Group b. It is a satellite galaxy of the Andromeda Galaxy c. It doesn't exist yet. It will be the galaxy that forms when the Milky Way and Andromeda Galaxies merge d. It is a member of the Leo Group e. It is a member of the Virgo Supercluster
c. It doesn't exist yet. It will be the galaxy that forms when the Milky Way and Andromeda Galaxies merge
What distance method is used to determine the distance to the most distant galaxies? Select one: a. Parallax b. Radar echo c. Supernova observations d. Period-luminosity relationship of variable stars
c. Supernova observations
____ is a form of electromagnetic radiation produced by rapidly moving electrons spiraling through magnetic fields. Select one: a. Lagrangian radiation b. Ultraviolet radiation c. Synchrotron radiation d. Accretion e. Infrared radiation
c. Synchrotron radiation
Which of the following is the largest object? Select one: a. The Milky Way galaxy. b. The Andromeda galaxy. c. The Local Group. d. The Large Magellanic Cloud.
c. The Local Group.
____ of the Milky Way contains mostly old (population II) stars and globular clusters. Select one: a. The spiral arms b. The disk component c. The spherical halo component d. The hydrogen gas in the disk e. Sgr A*
c. The spherical halo component
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 football b. a grain of sand c. a marble d. a basketball e. a baseball
c. a marble
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 naked black hole b. an active galaxy c. a quiescent black hole d. an infant black hole e. a mature black hole
c. a quiescent black hole
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. a shell of hot, expanding gas with a pulsar at the center.
Massive stars cannot generate energy through iron fusion because Select one: a. no star can get hot enough for iron fusion. b. massive stars supernova before they create an iron core. c. both fusion or fission of iron nuclei absorb energy d. iron fusion requires very high density. e. stars contain very little iron.
c. both fusion or fission of iron nuclei absorb energy
The Hubble Law is a relation between a galaxy's Select one: a. distance and its luminosity. b. mass and its luminosity. c. distance and its recession velocity. d. mass and its diameter. e. mass and its recession velocity.
c. distance and its recession velocity.
This force is what prevents a white dwarf from collapsing any further under the influence of gravity. Select one: a. proton degeneracy pressure b. radiation pressure from the nuclear fission of carbon c. electron degeneracy pressure d. radiation pressure from nuclear fusion of helium e. neutron degeneracy pressure
c. electron degeneracy pressure
While on the main sequence a star's primary energy source comes from a. nuclear fusion of hydrogen in the shell around the core b. nuclear fission of uranium in the core c. nuclear fusion of hydrogen in the core d. nuclear fusion of helium in the core e. nuclear fusion of hydrogen in the envelope
c. nuclear fusion of hydrogen in the core (fusing of hydrogen into helium which is called proton-proton chain)
A quasi-stellar radio source is now more commonly called a Select one: a. magnetar b. pulsar c. quasar d. neutron star e. supernova
c. quasar
A(n) ____ emits large amounts of energy but photographically appears to be a single point of light much like a star. Select one: a. spiral galaxy b. E galaxy c. quasar d. double-lobed radio galaxy e. a planet like Venus
c. quasar
If the theory that novae occur in close binary systems is correct, then novae should Select one: a. all be visual binaries. b. occur in regions of star formation. c. repeat after some interval. d. not occur in old star clusters. e. produce synchrotron radiation.
c. repeat after some interval.
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. squeeze you like a lemon c. spaghettify you d. affect your head more than your feet e. compress you into a tiny sphere
c. spaghettify you
One possible explanation for the weird, beautiful and fantastic shapes of planetary nebulae is that they Select one: a. are affected somehow by the intense magnetic field of their star b. rotate faster at the equator than the poles, causing material to be flung away from the equator faster c. swallowed some of their planets which then stirred the interiors of the stars d. are caused by the precession of the axis of the star e. spun faster at first then slowed as material was ejected
c. swallowed some of their planets which then stirred the interiors of the stars
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. the heavy elements were made in previous generations of stars.
About how far can we see before intstellar dust begins to block our view of the stars? Select one: a. 100 light years b. 550 light years c. 25 light years d. 1000 light years e. 50,000 light years
d. 1000 light years
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. 11.05 Billion Years b. 10.21 Billion years c. 46.75 Billion years d. 13.82 Billion years e. 4.76 Billion years
d. 13.82 Billion years
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 discovered 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. William Herschel b. Edmond Halley c. Edwin Hubble d. Galileo Galilee e. Christian Huygens
d. Galileo Galilee
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. IV b. II & IV c. I d. I & III e. I & IV
d. I & III
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. I, II, & III b. I & II c. IV d. III & IV e. II
d. III & IV
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. Cluster Group b. Family Cluster c. Family Group d. Local Group e. Related Cluster
d. Local Group
These galaxies have odd or distorted shapes and are all due to collisions between galaxies that are still occuring. Select one: a. Toroidal b. Elliptical c. Spiral d. Peculiar e. Irregular
d. Peculiar
What is the Hubble constant essentially a measure of? Select one: a. The number of galaxies in the universe. b. The age of the Milky Way galaxy. c. The amount of dark matter in an average galaxy. d. The expansion of the universe.
d. The expansion of the universe.
All of the following are types of galaxies except Select one: a. Irregular b. Elliptical c. Peculiar d. Toroidal e. Spiral
d. Toroidal
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. 100 kg (0.1 metric tons) c. a million tons d. a million grams (one metric ton) e. a billion grams (one thousand metric tons)
d. a million grams (one metric ton)
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. a proton star b. a black hole c. an electron star d. a neutron star e. a white dwarf
d. a neutron star
Planetary nebula typically glow for Select one: a. about a million years b. about 100 million years c. about 10 million years d. about 1000 years e. about 100 years
d. about 1000 years
5. In A.D. 1054, Chinese astronomers observed the appearance of a new star which they called a "guest star." When astronomers look at this place in the sky today, they can observe a. a pulsar b. a neutron star (more than 1.4 SM, less than 3 SM) c. a supernova remnant d. all of the above
d. all of the above (it was a type II supernova Crab Nebula)
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. an open cluster. b. a spherical component c. a globular cluster. d. an association. e. an accretion disk.
d. an association.
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 collapsing b. is expanding c. is made of metal-rich stars d. has spiral arms e. is very dusty
d. has spiral arms
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. neutrino pressure b. proton degeneracy pressure c. electron degeneracy pressure d. neutron degeneracy pressure e. radiation pressure
d. neutron degeneracy pressure
The age of the Milky Way galaxy has been estimated to be at least 13 billion years based on Select one: a. 21-cm radiation from H I regions. b. observations of open clusters. c. the rotation curve of the galaxy. d. observations of globular clusters. e. the energy produced by Sagittarius A*.
d. observations of globular clusters.
What do astronomers now think powers active galaxies? Select one: a. binary neutron stars b. binary red supergiant stars c. stellar mass black holes d. supermassive black holes e. co-orbiting neutron stars
d. supermassive black holes
A planetary nebula is Select one: a. a nebula within which planets are forming. b. a cloud of hot gas surrounding a planet. c. produced by a supernova explosion. d. the expelled outer envelope of a medium mass star. e. produced by a nova explosion.
d. the expelled outer envelope of a medium mass star.
Most of the globular clusters in the Milky Way are found in Select one: a. the galactic bar or bulge b. a ring around the edge of the Milky Way c. the Andromeda Galaxy d. the galactic halo e. the galactic disk
d. the galactic halo
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 merge and form a negatively charged neutron c. they annihilate each other and release light energy d. they merge and form a neutral neutron e. they form a positively charged prion
d. they merge and form a neutral neutron
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. 250 years b. 50 year c. 2.5 Million years d. 1,000 years e. 250,000 years
e. 250,000 years
About how long will a 0.5 star spend on the main sequence? Select one: a. 500 thousand years b. 570 million years c. 5 billion years d. 5 million years e. 57 billion years
e. 57 billion years
___________ 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. The velocity dispersion method b. A galaxy's color c. The Hubble constant d. A galaxy's diameter e. A galaxy's rotation curve
e. A galaxy's rotation curve
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. It will be sucked in because of the sun's increased gravitational field c. it will drift away from the sun due to the weakening of the gravitational field d. It will continue to orbit the black hole at its current radius e. Bad question. The sun will never be able to form a black hole
e. Bad question. The sun will never be able to form a black hole
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. novae b. pulsars c. supernovae d. neutron stars e. Cepheid variables
e. Cepheid variables
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. Either a. or b
According to Phil, where is the center of the universe? Select one: a. The center of mass of the Local Group of galaxies b. The Virgo supercluster of galaxies c. The supermassive black hole at the center of the Milky Way galaxy d. The center is approximately 35,000,000 LY from us in the direction of the constellation Cameleopardis. e. Every point in the universe looks like the center, so no point is actually the center of the universe
e. Every point in the universe looks like the center, so no point is actually the center of the universe
_____ occur when the moon is first or third quarter. a. Total solar eclipses b. Spring tides c. Annular eclipses d. A coppery red moon will e. Neap tides
e. Neap tides
Clusters of galaxies clump together to form larger structures known as ________________ which are held together by their mutual gravitational attraction. Select one: a. Supergroups b. Galaxy neighborhoods c. Galaxy spheres d. Gravitational webs e. Superclusters
e. Superclusters
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 smaller galasy will grow while the larger galaxy will shrink until they have approximately the same mass c. One will be ripped apart by tidal forces and the other will become more compact d. 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 e. They will eventually merge to form a single galaxy
e. They will eventually merge to form a single galaxy
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. a and b above
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. a and b above
A mega-parsec is equivalent to Select one: a. the diameter of the Milky Way galaxy. b. 206,265 AU c. 3.26 light-years. d. the age of our solar system e. a million parsecs.
e. a million parsecs.
The Crab nebula is Select one: a. an open cluster. b. a planetary nebula. c. a Bok globule. d. an absorption nebula. e. a supernova remnant.
e. a supernova remnant.
A Type I supernova is believed to occur when Select one: a. the core of a massive star collapses. b. neutrinos in a massive star become degenerate and form a shock wave that explodes the star. c. the cores of massive stars collapse. d. hydrogen detonation occurs. e. a white dwarf exceeds the Chandrasekhar limit.
e. a white dwarf exceeds the Chandrasekhar limit.
According to Phil, our solar system is located Select one: a. at the outer rim of the Milky Way b. about 1/4 of the way from the center to the edge of the Milk Way c. near the center of the Milky Way d. about 3/4 of the way from the center to the edge of the Milk Way e. about 1/2 of the way from the center to the edge of the Milk Way
e. about 1/2 of the way from the center to the edge of the Milk Way
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 reaches temperatures of millions of degrees and consequently emits a huge amount of light across the spectrum. Select one: a. singularity b. event horizon c. photosphere d. halo region e. accretion disk
e. accretion disk
A type-II supernova a. occurs when a white dwarf's mass exceeds the Chandrasekhar limit b. is the result of helium flash c. is characterized by a spectrum that shows hydrogen lines d. occurs when the iron core of a massive star collapses (iron is the limit of what stars can fuse; results in the remnants of neutrons aka neutron stars) e. c and d
e. c and d (Need more than 8 SM to have a Type II Supernova)
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. x-ray b. red visible c. ultraviolet d. infrared e. microwave
e. microwave
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. cosmic spinner b. rotator c. hydrodynamic engine d. spinor e. pulsar
e. pulsar
The period-luminosity relation is useful in determining Select one: a. the temperature of a star for which we know the luminosity. b. the radius of the bulge of our galaxy. c. the mass of the Milky Way galaxy. d. the mass of a star for which the distance is known. e. the distance to globular clusters that contain Cepheid variables.
e. the distance to globular clusters that contain Cepheid variables.
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 bowl b. the hat c. the stellar nursery d. the stellar graveyard e. the halo
e. the halo
10. The rocks on the surface of Titan appear smooth as though they have been weathered by being in a fluid flow. Which of the following is true about the rocks and fluids on Titan? a. the rocks are water ice and the fluid is water like the earth b. the rocks are water ice and the fluid is liquid nitrogen c. the rocks are silicates like earth and the fluid is water like the earth d. the rocks are silicates and the fluid is liquid nitrogen e. the rocks are water ice and the fluids are liquid hydrocarbons like methane and ethane
e. the rocks are water ice and the fluids are liquid hydrocarbons like methane and ethane Moon of Saturn and it has an atmosphere and is VERY cold!!
A star-like source of highly regular radio beeps is a ______.
quasar; quasi stellar radio sources produced by supermassive black holes tearing stars to shreds.
Type I supernovas are known as __________. Must have been _____ SM when it blew up. Compare absolute and apparent magnitude from that to determine the distance of the supernova.
the standard candle; 1.4