ASTRONOMY FINAL

This diagram represents an edge-on view of our Milky Way galaxy. Of the four labeled stars, which one could represent the Sun's position in the galaxy? A. Position 1 B. Position 2 C. Position 3 D. Position 4

A. Position 1

Which of these galaxies would you most likely find at the center of a large cluster of galaxies? A. a large spiral galaxy B. a large elliptical galaxy C. a small irregular galaxy

B. a large elliptical galaxy

Which of the following possible types of universe would not expand forever? A. a coasting universe B. an accelerating universe C. a critical universe D. a recollapsing universe

D. a recollapsing universe

What was the most important picture taken by humans ever?

Cosmic Microwave Background

Which transition, as shown, is not possible?

D.

This photo shows an object located in the halo of our Milky Way galaxy. What kind of object is it? A. A supergiant star B. An open cluster of stars C. A spiral galaxy D. A globular cluster of stars E. A "beehive" cluster

D. A globular cluster of stars

Study this H-R diagram. Which of the following stars is the largest in size (radius)? (The red arrows help you locate these stars on the diagram.) A. Canopus B. Aldebaran C. Alpha Centauri B D. Antares

D. Antares

At the center of the Sun, fusion converts hydrogen into: A. Photons B. Plasma C. Helium, carbon, and oxygen D. Helium, photons, and neutrinos

D. Helium, photons, and neutrinos

This diagram represents an edge-on view of our Milky Way galaxy. Of the four labeled stars, which one is located in what we call the halo of the galaxy? A. Star 1 B. Star 2 C. Star 3 D. Star 4

D. Star 4

Notice the well-defined spiral arms in this photograph of the galaxy M51. What makes the spiral arms so much brighter than regions between the arms? A. The presence of many hot interstellar bubbles in the spiral arms. B. The spiral arms are bright because nearly all the galaxy's stars are located within them. C. The presence of many old, red giant stars in the spiral arms. D. The presence of many massive young stars in the spiral arms.

D. The presence of many massive young stars in the spiral arms.

Notice the distorted galaxy images, such as the large arc-shaped structure, in this image of a galaxy cluster. What can astronomers learn by carefully measuring the distortions in this image? A. The precise distance to the galaxy cluster B. The age of the galaxy cluster C. The amount of dark energy in the universe D. The total mass of the cluster

D. The total mass of the cluster

These two diagrams contrast the habitable zones around the Sun and around a much lower mass star. They are shown to scale. Based on what you see here, what can you conclude about the possibility of finding life around the lower-mass star compared to finding life around a Sun-like star? A. A Sun-like star always has at least two habitable planets, while a lower-mass star may have only one habitable planet. B. There is virtually no chance of finding life around a lower-mass star. C. Sun-like stars must always have more life around them than lower-mass stars. D. There is a higher probability that an orbiting planet will be in the habitable zone for a Sun-like star than for a lower-mass star.

D. There is a higher probability that an orbiting planet will be in the habitable zone for a Sun-like star than for a lower-mass star.

This diagram shows several stages in a computer simulation of a collision between two galaxies. What happens? A. Two elliptical galaxies merge to become a spiral galaxy. B. Two galaxies collide, sending their stars flying off into space while their centers merge to become a supermassive black hole. C. Two spiral galaxies collide, ultimately merging to make a larger spiral galaxy. D. Two spiral galaxies merge to become an elliptical galaxy surrounded by debris.

D. Two spiral galaxies merge to become an elliptical galaxy surrounded by debris.

Express your answer using two significant figures. Galaxy 3: Speed away from us is 25000 km/s.

1100 million light years

what is the temperature of the cosmic microwave background?

2.7K

what is the % of energy in this universe?

5% ordinary matter, 25% dark matter, and 70% dark energy

Express your answer using two significant figures. Galaxy 1: Speed away from us is 15000 km/s.

680 million light years

Express your answer using two significant figures. Galaxy 2: Speed away from us is 20000 km/s.

910 million light years

Which of these stars does not have fusion occurring in its core? A. a red giant B. a red main-sequence star C. a blue main-sequence star

A a red giant

Study this H-R diagram. What is the spectral type of the star Sirius? (The red arrow helps you locate Sirius on the diagram.) A. A B. Blue C. 10^2 D. Main sequence

A. A

Which of these stars has the greatest surface temperature? A. A 30M main sequence star B. A supergiant star C. A cepheid variable star D. A main sequence M star

A. A 30M main sequence star

Suppose you had a time machine and traveled back in time to Earth about 3 billion years ago. Based on studying this diagram of the geological time scale, what would have caused you the most difficulty as you tried to walk around? A. A lack of breathable air B. The possibility of being harmed by poisonous plants C. The danger posed by carnivorous dinosaurs D. A lack of liquid water

A. A lack of breathable air

What do we need to do to determine a stars luminosity? A. Apparent brightness and distance B. Apparent brightness and temperature C. mass and distance D. Mass and temperature

A. Apparent brightness and distance

Which of the following correctly lists our "cosmic address" from small to large? A. Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe B. Earth, solar system, Local Group, Local Supercluster, Milky Way Galaxy, universe C. Earth, Milky Way Galaxy, solar system, Local Group, Local Supercluster, universe.

A. Earth, solar system, Milky Way Galaxy, Local Group, Local Supercluster, universe

This photo shows the Large Magellanic Cloud, or LMC for short. Based on what you have learned in about the LMC from your text, which of the following statements about the LMC is not true? A. Galaxies similar to the LMC are extremely rare. B. It is an irregular galaxy. C. It orbits the Milky Way galaxy. D. Its color indicates active star formation.

A. Galaxies similar to the LMC are extremely rare

This photo shows an undersea volcanic vent. What is it, and what is its significance to the study of the origin of life? A. Genetic studies suggest that life may have originated around vents like this one. B. It is the place where we have found the oldest fossils on Earth. C. It is the place where we have found the oldest living organisms on Earth. D. It shows that fires can burn underwater.

A. Genetic studies suggest that life may have originated around vents like this one.

What does this graph tell us about humans compared to other animals? A. Humans have a brain that is unusually large for an animal of our size. B. Based on averages determined from other animals, human brains are precisely the size we'd expect for animals of our weight. C. Unlike the brains of other animals, human brains cannot be described by a straight line. D. Humans have the largest brains of any animal.

A. Humans have a brain that is unusually large for an animal of our size.

This star map shows stars as we see them in our sky from Earth, centered around the constellation Canis Major. Larger dots represent brighter stars, and a few of the brightest stars are identified. From this view alone, what can you conclude about Sirius? A. It has the greatest apparent tightness of any star in this region of the sky. B. it is the nearest star in this region of the sky C. it is the most luminous star in this region of the sky

A. It has the greatest apparent tightness of any star in this region of the sky.

How does the habitable zone around a star of spectral type G compare to that around a star of spectral type M? A. It is larger. B. It is hotter. C. It is closer to its star.

A. It is larger.

What happens to the core of a high-mass star after it runs out of hydrogen? A. It shrinks and heats up. B. It shrinks and cools down. C. Helium fusion begins right away.

A. It shrinks and heats up.

Each dot on this graph represents an individual Cepheid variable star. Which of the following is true for a Cepheid that is 10,000 times as luminous as the Sun? A. It varies gradually in brightness, with a peak in brightness about every 30 days. B. It undergoes a massive flare about every 30 days. C. It orbits the center of the galaxy about every 30 days. D. It orbits its binary companion about every 30 days.

A. It varies gradually in brightness, with a peak in brightness about every 30 days.

This sequence of paintings represents the formation of the Milky Way galaxy. What law of nature explains why the galaxy began to rotate rapidly and flatten out as it shrunk in size? A. The law of conservation of angular momentum B. Einstein's special theory of relativity C. Newton's universal law of gravitation D. Newton's third law of motion

A. The law of conservation of angular momentum

Study this graph, focusing on the red curve and reddish horizontal swath. Which statement that follows correctly interprets what the graph shows? A. The measured abundance of deuterium agrees with the theoretically predicted abundance only if we make the prediction with a model of the universe in which ordinary matter makes up about 5% of the critical density. B. The abundance of deuterium in the universe has rapidly decreased with time. C. The abundance of deuterium in the universe is high in galaxies near the Milky Way but much lower in galaxies that are much farther away. D. The actual abundance of deuterium in the universe has never changed, but the predicted abundance has decreased with time.

A. The measured abundance of deuterium agrees with the theoretically predicted abundance only if we make the prediction with a model of the universe in which ordinary matter makes up about 5% of the critical density.

This graph shows the rotation curves of four different spiral galaxies. Based on these curves, what do all four galaxies have in common? A. Their most distant stars all orbit at about the same speed as stars located about 30,000 light-years from their centers. B. Their fastest-moving stars are always located within about 1,000 light-years of their centers. C. They all have supermassive black holes near their centers. D. All their stars take about 200 million years to complete a single orbit, no matter how far they are from the galactic center.

A. Their most distant stars all orbit at about the same speed as stars located about 30,000 light-years from their centers.

Suppose you visit the Moon..... A. Your mass would be the same on Earth, but your weight would be different. B. Your weight would be the same on Earth, but your mass would be different. C. Your mass and weight would both be the same as they are on Earth D. Your mass and weight would both be different than they are on Earth

A. Your mass would be the same on Earth but your weight would be different.

The theory of evolution is A. a scientific theory, meaning that it is backed by extensive evidence. B. one of several competing scientific models that all seem equally successful in explaining the nature of life on Earth. C. essentially just a guess about how life changes through time.

A. a scientific theory, meaning that it is backed by extensive evidence.

What would you be most likely to find if you returned to the solar system in 10 billion years? A. a white dwarf B. a neutron star C. A black hole D. A supernova remnant

A. a white dwarf

Which of these binary systems is most likely to contain a black hole? A. an X-ray binary containing an O star and another object of equal mass B. a binary with an X-ray burster C. an X-ray binary containing a G star and another object of equal mass

A. an X-ray binary containing an O star and another object of equal mass

Stars can form most easily in clouds that are A. cold and dense B. warm and dense C. hot and low-density

A. cold and dense

How would the wavelength of the photon involved in transition A compare to that of the photon wavelength in transition C? A. it would be shorter B. it would be longer C. it would be more intense D. it would be less intense

A. it would be shorter

This figure shows observations over more than a decade that have allowed us to determine the orbits of several stars around Sgr A* (the central object). What can we learn about Sgr A* by analyzing these orbits? A. its mass B. its age C. its chemical composition D. all of the answers

A. its mass

Two stars that are in the same constellation: A. may be far from each other in space B. are the same distance from us C. must be near each other in space D. must have been discovered at about the same time

A. may be far from each other in space.

solar energy leaves the core of the Sun in the form of A. photons B. rising hot gas C. sound waves

A. photons

Based on this diagram, "red sequence" galaxies are __________ than "blue cloud" galaxies. A. redder and more luminous B. redder and more distant C. cooler and more distant D. more luminous and older

A. redder and more luminous

In the spectrum of a star, you observe an emission line at a wavelength of 630 nm. In the laboratory, this line has a wavelength of 600 nm. The emission line from the star is: A. redshifted B. blue shifted C. skewed D. dampened

A. redshifted

Consider a spinning disk of pizza dough, as shown here. What would the rotation curve for the spinning dough look like? A. straight line up B. curved like an L C. straight line down D. straight line across

A. straight line up

Based on current evidence, which of the following is considered a likely candidate for the majority of the dark matter in galaxies? A. subatomic particles that we have not yet detected B. swarms of dim, red stars C. supermassive black holes

A. subatomic particles that we have not yet detected

In winter, Earth's axis points toward the star Polaris. In spring: A. the axis also points toward Polaris. B. the axis points toward Vega. C. the axis points toward the Sun.

A. the axis also points toward Polaris

This photograph shows an interstellar bubble about 10 light-years in diameter. If you could photograph this same region about 100 years from now, how would you expect it to look different? A. The bubble will be slightly larger B. The bubble will have burst as a supernova C. The bubble will be slightly smaller D. The bubble's shape will have become much more like an oval rather than a sphere

A. the bubble will be slightly larger

what two pieces of information would you need in order to measure the masses of stars in a eclipsing binary system? A. the time between eclipses and the average distance between the stars B. the period of the binary system and its distance from the Sun C. the velocities of the stars and the Doppler shifts of their absorption lines

A. the time between eclipses and the average distance between the stars

The fact that nearly all galaxies are moving away from us, with more distant ones moving faster, helped us to conclude that A. the universe is expanding. B. galaxies repel each other like magnets. C. our galaxy lies near the center of the universe.

A. the universe is expanding

This photograph shows x-ray emission from a supernova remnant. what is the source of the x-rays? A. very hot gas expanding outward from the site of a supernova B. cold gas that will soon give birth to new stars C. spots within the remnant where hot gas is crashing into and destroying planets D. accretion disk around a black hole near the center of the supernova remnant

A. very hot gas expanding outward from the site of a supernova

The labeled transitions (A-E) represent an electron moving between energy levels in hydrogen. Circle the correct answer. Which transition could represent an atom that absorbs a photon with 10.2 eV of energy?

B.

This diagram represents an edge-on view of our Milky Way galaxy. Of the four labeled stars, which one is located closest to a place where evidence suggests we would find a 4-million-solar-mass black hole? A. 1 B. 2 C. 3 D. 4

B. 2

The speed of light (in a vacuum) and a light year are, respectively: A. 300,000 miles per hour and the distance light travels in one year. B. 300,000 km per sec and the distance light travels in one year. C. 300,000 km per sec and the time it takes for light to travel in one year. D. 300,000 km per sec and the distance to the nearest star.

B. 300,000 km per sec and the distance light travels in one year.

What is this a picture of? A. The expanding universe B. A cluster of galaxies C. A globular cluster D. An elliptical galaxy

B. A cluster of galaxies

This figure shows a "slice of the universe" from the Sloan Digital Sky Survey. What is the Sloan Great Wall (indicated by the arrow)? A. A hypothesized structure built of the particles responsible for creating dark energy in the universe B. A huge collection of galaxies extending a billion light-years in length C. Our cosmological horizon, the point beyond which we cannot see D. A giant wall of hot gas extending a billion light-years in length

B. A huge collection of galaxies extending a billion light-years in length

The bright object in this photo is a quasar in the center of a distant galaxy. According to current understanding, about how big is the source of the bright light? A. About a million light-years across B. About the size of our solar system C. About the size of the central bulge of the Milky Way Galaxy (that is, about 10,000 light-years across) D. About 500 light-years across

B. About the size of our solar system

These diagrams represent four possible models for the universe. Each model shows how the size of the observable universe changes with time. Of the four models, which one gives the universe the oldest age at present? A. The age of the universe would be the same no matter which model is correct B. Accelerating universe C. Coasting universe D. Recollapsing universe E. Critical universe

B. Accelerating universe

Study this H-R diagram. Which of the following stars has (or had) the longest hydrogen burning lifetime? (The red arrows help you locate these stars on the diagram.) A. Betelgeuse B. Barnard's star C. The Sun D. Alpha Centauri B

B. Barnard's star

Study this H-R diagram. Which of the following stars is the most massive? (The red arrows help you locate these stars on the diagram.) A. DX Cancri B. Beta Centauri C. Bellatrix D. Vega

B. Beta Centauri

The data points in this diagram represent the measured speeds and distances of various galaxies, and the solid line represents a best fit to these data. The trend indicated by the solid line is known as _________. A. the period-luminosity relation B. Hubble's law C. Kepler's third law D. the inverse square law for light

B. Hubbles Law

The top panorama shows our view of the Milky Way in all directions as it appears in visible light. The bottom panorama shows the same view but in a different wavelength of light. What wavelength band are we seeing in the bottom photo, and how do you know? A. Radio waves, because clouds of gas in the disk of our galaxy appear pinkish when we look at them with radio telescopes. B. Infrared light, because the dust that appears dark in the visible light photo glows in infrared light. C. X-ray light, because only X-rays allow us to see through the disk of our galaxy. D. Infrared light, because clouds of gas and dust appear pinkish when we look at them with infrared telescopes.

B. Infrared light, because the dust that appears dark in the visible light photo glows in infrared light.

This photo shows a radio telescope that is being used in the search for life beyond Earth. How is it being used in this search? A. It is used to communicate with spacecraft that we have launched toward distant stars in search of life on planets that my orbit them. B. It is used to listen for signals deliberately broadcast by another civilization. C. It is used to make detailed radar maps of Mars, from which we may be able to determine whether cities ever existed on our planetary neighbor. D. It is used to obtain spectra of planets around other stars so that we can look for chemicals, like oxygen, that might indicate the presence of life.

B. It is used to listen for signals deliberately broadcast by another civilization.

This image shows a colliding pair of galaxy clusters known together as the Bullet Cluster. The blue region represents a map of the cluster's dark matter. How was this blue map made? A. The blue region represents X-ray emission from hot gas within the cluster. B. The blue region was inferred from studies of how the cluster causes gravitational lensing of objects located behind it. C. The blue region comes from the combined light of many young stars drawn together by the cluster's dark matter. D. The blue region represents previously unknown radio emission from the dark matter.

B. The blue region was inferred from studies of how the cluster causes gravitational lensing of objects located behind it.

This famous image from the Hubble Space Telescope shows what is sometimes called the "pillars of creation." Which of the following best describes what it shows? A. Each of the pillars is a cloud of gas that will give birth to a single star, which will emerge from the top of its pillar. B. The pillars are clouds of gas and dust in which many new stars are forming; the edges of the pillars are sculpted by ultraviolet radiation from stars outside the pillars. C. There is a hot, young star at the top of each pillar that is shooting a jet of gas that forms the pillar below the star. D. There is a single star outside the frame at the bottom, and the pillars are clouds of accreting particles that will form planets orbiting the star.

B. The pillars are clouds of gas and dust in which many new stars are forming; the edges of the pillars are sculpted by ultraviolet radiation from stars outside the pillars.

This photo shows apparatus used in an experiment in which materials thought to have been present on the early Earth were sparked with energy. What have we learned from this type of experiment? A. These experiments have told us the precise composition of Earth's early atmosphere. B. These experiments have shown that the building blocks of life form easily and naturally under conditions that existed on the early Earth. C. These experiments have provided strong evidence for the idea that life first arose near volcanic vents at the bottom of the ocean. D. These experiments have shown us how life originated on Earth.

B. These experiments have shown that the building blocks of life form easily and naturally under conditions that existed on the early Earth.

A brown dwarf is: A. a white dwarf that has cooled off B. an object not quite massive enough to be a star C. A star like object that is less massive than Jupiter D. the final stage of the life sequence of a low mass star

B. an object not quite massive enough to be a star

The set of spectral lines that we see in a star's spectrum depends on the star's: A. interior temperature B. chemical composition C. rotation rate

B. chemical composition

What are the dark blobs (indicated by the red arrows) in this photograph from the Hubble Space Telescope? A. warm atomic hydrogen gas, much like most of the gas in the galaxy B. cold, dense molecular clouds in which stars are forming C. jets of hot gas shot out from young binary star systems D. tall interstellar bubbles blown out by supernovae or stellar winds

B. cold dense molecular clouds in which stars are forming

Which lists the major steps of solar system formation in the correct order? A. collapse, accretion, condensation B. collapse, condensation, accretion C. accretion, condensation, collapse D. accretion, collapse, condensation

B. collapse, condensation, accretion

To make a rocket turn left, you need to: A.fire an engine that shoots out gas to the left. B. fire an engine that shoots out gas to the right. C. spin the rocket clockwise D. spin the rocket counterclockwise.

B. fire an engine that shoots out gas to the right

A car is accelerating when it is... A. traveling on a straight, flat road at 50 miles per hour. B. going around a circular track at a steady 100 miles per hour. C. traveling on a straight uphill road at 30 miles per hour. D. cant tell with the info given.

B. going around a circular track at a steady 100 miles per hour

Compared to red light, blue light has higher frequency and... A. higher energy and longer wavelength. B. higher energy and shorter wavelength. C. lower energy and shorter wavelength. D. lower energy and longer wavelength

B. higher energy and shorter wavelength

What would happen to a neutron star with an accretion disk orbiting in a direction opposite to the neutron star's spin? A. its spin would speed up B. its spin would slow down C. its spin would stay the same D. its spin would begin to wobble (precession)

B. its spin would slow down

According to current understanding, the key requirement for life is A. photosynthesis. B. liquid water. C. an ozone layer.

B. liquid water.

Given the spectral information from Q10, the star is: A. moving towards us B. moving away from us. C. moving sideways with respect to us. D. can't tell with the info given.

B. moving away from us.

Fossil evidence suggests that life on Earth arose A. almost immediately after Earth formed. B. within a few hundred million years after Earth formed. C. about a billion years before the rise of the dinosaurs.

B. within a few hundred million years after Earth formed.

How large an object causes a typical shooting star? A. A mountain B. A boulder C. An object the size of a car. D. a grain of sand or a small pebble

D. a grain of sand or a small pebble

The labeled transitions (A-E) represent an electron moving between energy levels in hydrogen. Circle the correct answer. Which transition could represent an atom that emits a photon with 10.2 eV of energy?

C.

Which of the following is not true about a scientific theory? A. A theory must explain a wide range of observations or experiments. B. A theory is stronger than a hypothesis, and weaker than a law. C. A theory is essentially an educated guess. D. Even the strongest theories can never be proved true beyond all doubt.

C. A theory is essentially an educated guess.

Which kind of star is most likely to be part of the spheroidal population? A. AN O STAR B. AN A STAR C. AN M STAR

C. AN M STAR

If you looked at the field of view seen in this Hubble Space telescope with your naked eye, about how big would it appear in the sky? A. about the size of the Big Dipper B. About the size of the full moon C. About the size of this period — . — viewed at arm's held at arm's length against the sky. D. About the size of your little finger held at arms length against the sky

C. About the size of this period — . — viewed at arm's held at arm's length against the sky.

These diagrams represent four possible models for the universe. Which model presumes the existence of some type of dark energy in the universe? A. All four models assume the existence of dark energy B. Recollapsing universe C. Accelerating universe D. Coasting universe E. Critical universe

C. Accelerating Universe

This photo shows the famous Crab Nebula. What is it? A. A classic example of a planetary nebula. B. A star-forming cloud that will eventually give birth to hundreds of stars C. An expanding cloud of remains from a star that died in a supernova. D. A star that is right now undergoing a supernova explosion.

C. An expanding cloud of remains from a star that died in a supernova.

Why do virtually all the galaxies in the universe appear to be moving away from our own? A. Because we are located near where the Big Bang happened. B. Because we are located near the center of the universe. C. Because expansion causes all galaxies to move away from nearly all others.

C. Because expansion causes all galaxies to move away from nearly all others.

In this diagram, red balls represent protons and gray balls represent neutrons. What reaction is being shown? A. Fusion of carbon into oxygen B. The "iron catastrophe" that initiates a supernova C. Fusion of helium into carbon D. Fusion of hydrogen into helium

C. Fusion of helium into carbon

WHERE ARE MOST OF THE MILKY WAY'S GLOBULAR CLUSTERS FOUND? A. IN THE DISK B. IN THE BULGE C. IN THE HALO

C. IN THE HALO

This photo shows gas associated with a protostar. What is this gas doing? A. It is part of a protostellar disk in which planets may someday form. B. It is gas blown off the protostar's surface as a protostellar wind. C. It is flowing outward in two opposite directions from the protostar. D. It is gas that is gradually accreting onto the protostar.

C. It is flowing outward in two opposite directions from the protostar.

This diagram shows the "tree of life" based on genetic studies of relationships between living organisms. Which statement about the tree of life is not true? A. It shows that all organisms alive today bear genetic similarities that suggest they evolved from a common ancestor. B. It shows that there is greater genetic diversity in microscopic organisms than among animals. C. It shows that plants and animals are the two most dominant forms of life on Earth today. D. It shows that, based on genetic relationships, there are three major branches of life on Earth.

C. It shows that plants and animals are the two most dominant forms of life on Earth today.

The arrow in the photo on the left points to the star that we see as a supernova in the photo on the right. What can we conclude about this star? A. Before the supernova, the star lived for at least a billion years. B. It was a red giant star. C. It was a high-mass star with at least 8 times the mass of the Sun. D. It was a close binary star system.

C. It was a high-mass star with at least 8 times the mass of the Sun.

This painting shows a futuristic spacecraft powered by the detonation of small hydrogen bombs. If we actually had such a spacecraft, what would it allow us to do? A. It would allow us to travel from Earth to Mars in less than an hour. B. It would allow us to travel roundtrip to almost anywhere in the Milky Way galaxy in just a few years' time. C. It would allow us to make a one-way trip to the nearest star besides the Sun in about a century. D. It would allow us to travel up to several times faster than the speed of light.

C. It would allow us to make a one-way trip to the nearest star besides the Sun in about a century.

The best measurements of the mass of the black hole at the galactic center come from A. THE ORBITS OF GAS CLOUDS IN A GALACTIC CENTER B. THE AMOUNT OF RADIATION FROM THE GALACTIC CENTER C. THE ORBITS OF STARS IN THE GALACTIC CENTER

C. THE ORBITS OF STARS IN THE GALACTIC CENTER

This graph shows how the average distances between galaxies changes with time in the four models for the universe and also shows data points measured from white dwarf supernovae. Which of the following statements best describes what the data are telling us? A. The data prove beyond doubt that we live in an accelerating universe that will continue to expand forever. B. The data prove beyond doubt that the universe will never collapse. C. The data indicate that we live in an accelerating universe. D. The data strongly suggest that our universe is made 95% of dark matter and only 5% of ordinary matter.

C. The data indicate that we live in an accelerating universe.

Why do some of the bright stars (such as the one indicated by the arrow) in this photo have cross-shaped spikes over them? A. Very bright stars tend to be slightly non-spherical in shape and therefore look like they have spikes in photos. B. The stars with spikes are actually binary star systems. C. The spikes are an artifact of photography through a telescope. D. The spikes are flares ejected from the surfaces of bright stars.

C. The spikes are an artifact of photography through a telescope.

This photo shows a boy playing with sand on the beach. If we think about the grains of sand, how are they significant to the question of life beyond Earth? A. There are about as many habitable planets orbiting other stars in the universe as there are grains of sand on all the beaches on Earth. B. We think that life must always arise on or near an ocean, so this scene on the beach probably looks much like what we'd expect to find on any other planet with life on it. C. There are about as many stars in the universe as there are grains of sand on all the beaches on Earth, so there are a lot of possible homes to life. D. There are about as many life-bearing planets in the universe as there are grains of sand on all the beaches on Earth.

C. There are about as many stars in the universe as there are grains of sand on all the beaches on Earth, so there are a lot of possible homes to life.

What are the different colored horizontal layers that we see in this photo of a wall in the Grand Canyon? A. They got their coloration from ancient civilizations that painted the rock. B. They are different types of volcanic rock that cooled at different rates after a single, large volcanic eruption. C. They are sediments deposited at different times in the past, so that layers near the bottom are the oldest and layers near the top are the youngest. D. They formed as the Colorado River carved out the canyon, so that the layers near the top are the oldest and the layers at the bottom are the youngest.

C. They are sediments deposited at different times in the past, so that layers near the bottom are the oldest and layers near the top are the youngest.

A photograph of a cluster of galaxies shows distorted images of galaxies that lie behind it at greater distances. This is an example of what astronomers call: A. dark energy. B. spiral density waves. C. a gravitational lens.

C. a gravitational lens.

Which kind of object is the best standard candle for measuring distances to extremely distant galaxies? A. a white dwarf B. a Cepheid variable star C. a white dwarf supernova

C. a white dwarf supernova

What causes the cycle of solar activity? A. changes in the speed of the solar wind B. changes in the Suns fusion rate C. changes in the organization of the Sun's magnetic field D. Pulsations inside the Sun

C. changes in the organization of the Sun's magnetic field

Where do gamma-ray bursts tend to come from? A. neutron stars in our galaxy B. black holes in our galaxy C. extremely distant galaxies

C. extremely distant galaxies

The gravitational potential energy of a contracting interstellar cloud... A. stays the same at all times. B. gradually grows larger. C. gradually transforms into other forms of energy. D. gradually dissipates.

C. gradually transforms into other forms of energy.

The primary source of a quasar's energy is A. chemical energy. B. nuclear energy. C. gravitational potential energy.

C. gravitational potential energy

The composition of the solar nebula was 98%: A. rock and metal B. hydrogen compounds C. hydrogen and helium D. rainbows and unicorns

C. hydrogen and helium

When we say that a planet has a highly eccentric orbit, we mean that: A. it is spiraling in toward the Sun. B. its orbit is an ellipse with the Sun at one focus. C. in some parts of its orbit it is much closer to the Sun than in other parts.

C. in some parts of its orbit it is much closer to the Sun than in other parts

Is this a photo of a spiral galaxy or an elliptical galaxy, and how do you know? A. It is an elliptical galaxy, because it looks red/yellow in color. B. It is an elliptical galaxy, because it is elliptical in shape. C. It is a spiral galaxy, because we can see a dusty disk going across the center. D. It is a spiral galaxy, and we know because photos of this same galaxy from above show its spiral arms.

C. it is a spiral galaxy because we can see a dusty disk going across the center.

Viewed from a distance, how would a flashing red light appear as it fell into a black hole? A. It would appear to flash more quickly. B. Its flashes would appear bluer. C. Its flashes would shift to the infrared part of the spectrum.

C. its flashes would shift to the infrared part of the spectrum

Some jovian planets give off more energy than they receive because of: A. fusion in their cores B. tidal heating C. ongoing contraction or differentiation. D. the solar wind.

C. ongoing contraction or differentiation

This image combines a visible light view of the galaxy Hercules A with an image showing radio wave emission (the reddish colors) in its vicinity. The likely explanation for the two huge clumps of radio emission far to either side of the visible galaxy is _________. A. the radio emission comes from gas pulled out of the galaxy when it collided with another galaxy in the distant past B. this galaxy must have suffered two collisions in the past, with each collision pulling out gas in one direction C. the radio emission comes from gas shot out into space by jets powered by a supermassive black hole in the galactic center D. the radio emission comes from gas that was left behind in the halo when the galaxy collapsed from a protogalactic cloud

C. the radio emission comes from gas shot out into space by jets powered by a supermassive black hole in the galactic center

why do sunspots appear darker than their surroundings? A. they block some of the sunlight from the photosphere B. they do not emit any light C. They are cooler than their surroundings D. they are composed of dark matter

C. they are cooler than their surroundings

Dark matter is inferred to exist because: A. we see lots of dark patches in the sky. B. it explains how the expansion of the universe can be accelerating. C. we can observe its gravitational influence on visible matter.

C. we can observe its gravitational influence on visible matter.

Notice the blue ovals (such as those indicated by the arrows) in this image of a galaxy cluster. The oval structures are not really located where they appear to be, but instead are multiple images of a single galaxy that lies directly behind the cluster. What do we call the process that creates these multiple images? A. dark energy B. The arc effect C. cluster image distortion D. gravitational lensing

D. gravitational lensing

The Earth has seasons because: A. its orbit brings it closer to the Sun at certain times of the year. B. the atmosphere stores energy and releases it as heat in a yearly cycle. C. it wobbles which causes one hemisphere to be closer to the Sun than the other. D. its axis of rotation is tilted which causes one hemisphere to receive more direct sunlight than the other.

D. its axis of rotation is tilted which causes one hemisphere to receive more direct sunlight than the other.

The force of gravity is given by: F= GMm/r^2. If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be... A. one-third as strong. B. twice as strong. C. half as strong. D. one-quarter as strong.

D. one quarter as strong.

The star Betelgeuse is about 600 light-years away. If it explodes tonight: A. we'll know because it will be brighter than the full Moon in the sky. B. we'll know because debris from the explosion will rain down on us from space. C. we'll know it exploded if we repeat the word "Betelgeuse" three times. D. we won't know it exploded until 600 years from now.

D. we won't know it exploded until 600 years from now.

The labeled transitions (A-E) represent an electron moving between energy levels in hydrogen. Circle the correct answer. Which transition could represent an electron that is breaking free of the atom?

E.

This photo shows an object located in the halo of our Milky Way galaxy. Notice the many bright red dots in the photograph. What are they? A. Massive supergiant stars B. Cool, red main-sequence stars of spectral type M C. Old white dwarf stars that have turned red in color D. Starspots E. Red giant stars

E. Red giant stars

On average, how many stars would we have to search before we would expect to hear a signal? Assume there are 500 billion stars in the galaxy. Express your answer using one significant figure.

N1 = 5×10^7

How does your answer change if there are only 100 civilizations instead of 1×10^4? Express your answer using one significant figure.

N2 = 5×10^9

What does the cosmic microwave background show?

showing residual heat leftover from the big bang

what 2 things does life need to survive?

a solvent in which chemical reactions may occur and a source of energy (sunlight, chemical reactions, etc)

what does the cosmic microwave background confirm?

that inflation happened because of red and blue pixels / regions and how big they are

what is the leftover radiation from the Big bang?

the Cosmic Microwave background

What type of universe do we have?

accelerating

which one these layers of the sun is the coolest? A. chromosphere B. corona C. ionosphere D. photosphere

d. photosphere

Would transition A represent emission or absorption of light?

emission

when this radiation was emitted in the cosmic microwave background , what wavelength was it emitted at?

it was first emitted in visible light

what wavelength is the cosmic microwave background currently seen in?

microwaves

what are the 7 traits of life?

organization, homeostasis, metabolism, growth, stimuli, stimuli, adaptation, reproduction

in the cosmic microwave background, this image as you see it is red and blue pixels. what do those mean?

red is slightly hotter than average temps and blue is slightly colder than average

what is the inflationary theory?

the idea that there was a time during the early universe where the expansion was greater than at any other time in the history of the universe

why do you think the cosmic microwave background used to be shorter wavelengths?

the universe has expanded so the wavelengths have been shifted

what is the difference between catabolism and anabolism?

they are both forms of metabolism. anabolism builds up and catabolism breaks down. living organisms normally have both of these

what do the best maps of the cosmic microwave background reveal?

tiny fluctuations in temperature and density