NAME _______________________________                     LAB # ____________________

Astronomy 1001 - Final Exam - May 13, 2005                             Dr. Liliya Williams, Spring 2005

Read Instructions Carefully:

1.         MARK THE ANSWERS YOU CHOOSE ON THIS TEST AS IT IS YOUR ONLY

            OPPORTUNITY TO CHECK WHICH ANSWERS YOU GOT RIGHT OR

            WRONG. This will not be done for you at a later time in the departmental office.

Exams will be available in room 451 Physics during Summer Session TA office hours.

2.         Print your NAME, ID # and SECTION # on your answer sheet where appropriate. Your

            SECTION # should read 01. All three items are necessary for the proper scoring and

            computer transfer of your scores.

3.         Use a pencil, make your marks dark and neat, and erase thoroughly.

4.         There is only one answer to each question. Choose the best answer.

5.         You may use this test for scratch paper.

6.         One page (two sides) of notes is allowed for the exam

MULTIPLE CHOICE (3.5 pts each)

1. If the Moon is high in the sky at midday, its phase is

(a) new            (b) first quarter           (c) third quarter          (d) full            (e) waning crescent

2. If the Earth did not have its Moon which one of the following would not occur?

(a) Solar eclipses

(b) Lunar eclipses

(c) ocean tides

(d) phases of the Moon

(e) all of the above

3. The ozone layer in the Earth's atmosphere

(a) absorbs Ultra-Violet photons from the Sun

(b) has been increasing in thickness over the last few decades

(c) is responsible for the greenhouse effect

(d) consists mostly of Nitrogen ions

(e) all of the above are correct

4. Jupiter's satellite Io is well known to most Astronomy students because it is

(a) the only satellite of Jupiter

(b) fully covered with oceans of frozen water

(c) the most volcanically active body in the Solar System

(d) in the process of exploding

(e) an artificial (i.e. man-made) satellite

5. If the Earth is suddenly transformed into a ball of lead of the same mass as the present Earth, how would its orbit around the Sun change?

(a) its semi-major axis will increase

(b) its semi-major axis will decrease

(c) the orbit will become more elliptical

(d) the orbit will become more circular

(e) the orbit will not change at all

6. The Geocentric model of the Solar System was finally discarded because it could not account for the

(a) retrograde motion of planets

(b) fact that planets' always stayed close to the ecliptic

(c) Solar System's nine planets

(d) observed phases of Venus

(e) seasons

7. Suppose the Earth's rotation axis were not tilted with respect to the ecliptic. How would that affect the number of hours of daylight?

(a) there would be more daylight in summer and less in winter;

(b) there would be fewer hours of daylight in summer than in winter;

(c) it would not alter the present situation;

(d) the number of hours of daylight would be the same throughout the year;

(e) it would not affect the number of hours of daylight, but it would make the day only 12 hours long.

8. Sunspots on the surface of the Sun look dark because

(a) the Sun rotates differentially

(b) they are holes on the Sun's surface

(c) their temperature is lower than that of the rest of the surface

(d) their temperature fluctuates rapidly

(e) their chemical composition is different from that of the rest of the Sun

9. Sun is powered by

(a) chemical reactions, similar to burning of coal

(b) mechanical energy that comes from Sun's rotation

(c) electromagnetic energy

(d) nuclear reactions converting Hydrogen to Helium

(e) nuclear reactions converting Uranium to Lead

10. 21 cm line emitted by Hydrogen is in the _______ part of the electromagnetic spectrum

(a) gamma-ray            (b) X-ray         (c) optical       (d) microwave            (e) radio

11. HR diagram of a star cluster can be used to determine cluster's

(a) age

(b) velocity away or towards us

(c) chemical composition

(d) gas and dust content

(e) all of the above

12. Our Sun's future evolutionary stages include

(a) red giant, planetary nebula, and white dwarf

(b) red giant, recurrent novae, and white dwarf supernova

(c) neutron star, and pulsar

(d) red giant, Cepheid, and black hole

(e) red giant, and pulsar

13. Compared to a main sequence star, a white dwarf

(a) is supported against collapse by electron degeneracy pressure

(b) is supported against collapse by neutron degeneracy pressure

(c) is supported against collapse by gas pressure

(d) has nuclear fusion going on in the core

(e) has nuclear fusion going on in a shell around the core

14. Accretion disks are common in astronomy. They are the result of

(a) nuclear fusion reactions

(b) nuclear fission reactions

(c) conservation of mass-energy

(d) conservation of linear momentum

(e) conservation of angular momentum

15. Elements with atomic numbers higher than iron's were created in

(a) planetary nebula

(b) massive main sequence stars

(c) low mass red giant stars

(d) nova outbursts

(e) supernova explosions

16. Planetary nebula

(a) are gas clouds around outer planets in the Solar System

(b) are always spherical

(c) can be used to measure distances to galaxies

(d) are remnants of the early Universe

(e) are the outer shells of solar-type stars ejected during the end stages of a star's life

17. What is the definition of a black hole?

(a) any compact mass that emits no light

(b) a dead star that has faded from view

(c) any object from which the escape velocity equals the speed of light

(d) any object made from dark matter

(e) a dead galactic nucleus

18. Cepheids are important in astronomy because

(a) it is possible to measure their masses directly

(b) they always occur in clusters

(c) they always occur in binaries

(d) they exhibit large parallaxes

(e) it is possible to measure distance to them

19. What is the best example of a Thermal or Black Body radiator?

(a) stars

(b) planets

(c) clouds of gas and dust

(d) galaxies

(e) cosmic microwave background

20. If a young star cluster is surrounded by a diffuse dusty cloud, the cluster will appear to you as a

(a) Cepheid

(b) quasar

(c) planetary nebula

(d) red reflection nebula

(e) blue reflection nebula

21. A merger of two spiral galaxies can result in

(a) accelerated expansion of the Universe

(b) decelerated expansion of the Universe

(c) the formation of an elliptical galaxy

(d) a Supernova explosion

(e) decreased quasar activity at the center of the newly formed body

22. The typical density of material in the interstellar medium of galaxies is

(a) comparable to the density of water

(b) smaller than the density of the best vacuum we can make on Earth

(c) larger than the density at the center of the Earth

(d) much smaller than the density of material between clusters of galaxies

(e) unknown

23. The first stars to form in our Galaxy

(a) contained a lot of iron and lead in their atmosphere

(b) have all exploded by now

(c) are found only in the disk of the Galaxy

(d) were made up almost entirely of Hydrogen and Helium

(e) came from elliptical galaxies

24. The size of dust grains in the interstellar medium is similar to the wavelength of ________ electromagnetic radiation, therefore ________ radiation is not affected by dust.

(a) radio; blue

(b) radio; X-ray

(c) X-ray; Ultra Violet

(d) microwave; Ultra Violet

(e) blue; radio

25. Rotation curves of spiral galaxies imply that

(a) most of the mass of galaxies is contained at their centers

(b) the amount of mass contained in stars is equal to that in gas

(c) there is more mass in the galaxies than what is contained in stars and gas

(d) there is a lot of dark dust present in galaxies

(e) galaxies obey Hubble Law

26. Which of the following is/are not a part of our Galaxy's disk?

(a) spiral arms

(b) open clusters

(c) globular clusters

(d) the Solar System

(e) emission nebulae

27. Collisions between galaxies

(a) were more common in the past than now

(b) are more common now than they were in the past

(c) lead to formation of spiral galaxies

(d) lead to formation of ellipticals

(e) both (a) and (d)

28. What type of galaxies are forming stars at the present time and why?

(a) Ellipticals; because they have large supplies of gas

(b) Ellipticals; because they have little or no gas in them

(c) Ellipticals; because they are very dense systems

(d) Spirals; because they have large supplies of gas

(e) Spirals; because they are similar to our Milky Way Galaxy

29. Kepler's 3rd law can be used to measure the mass of

(a) the Sun

(b) the Galaxy

(c) the supermassive black hole in the center of the Galaxy

(d) masses of cluster of galaxies

(e) all of the above

30. What do spiral and elliptical galaxies have in common?

(a) the orbits of their stars have similar shapes

(b) both types of galaxies contain similar numbers of young stars

(c) both types of galaxies can be found at the centers of galaxy clusters

(d) both types of galaxies contain large amounts of dark matter

(e) all of the above

31. Of the following, what is/are the most likely dark matter candidate(s)?

(a) an unknown type of elementary particle

(b) anti-particles of protons, neutrons, electrons

(c) neutrinos

(d) planets, white dwarfs, neutron stars and black holes

(e) supermassive black holes at the centers of galaxies

32. We know that the center of our Galaxy hosts a black hole because

(a) we detect gamma-ray emission from the center

(b) we detect radio emission from the center

(c) we measure large Doppler velocities of the stars close to the center

(d) we see many stars close to the center

(e) we cannot see the center of the Galaxy at optical wavelengths

33. Which one of the following CANNOT be used to measure distances to galaxies?

(a) a relation between galaxies' luminosities and rotational velocities

(b) Cepheids' relation between luminosities and pulsation periods

(c) luminosities of White Dwarf Supernovae

(d) Hubble diagram

(e) trigonometric parallax

34. The observable horizon of the Universe

(a) always increases with time

(b) was much larger during Big Bang Nucleosynthesis epoch than it is now

(c) is currently comparable to the size of the Milky Way Galaxy

(d) will shrink in the future

(e) is a concept we did not discuss in class

35. What is the correct statement about the expansion of our Universe? The expansion

(a) rate has been the same since the beginning

(b) is currently decelerating

(c) is currently accelerating

(d) rate is unknown

(e) rate depends on the type of standard candle used to measure it

36. Suppose you want to observe a Globular Cluster in our Galaxy. To obtain best possible data you should pick a telescope with

(a) large primary mirror

(b) small primary mirror

(c) a remote control

(d) large magnification

(e) large secondary mirror

37. The age of the Universe is about

(a) 10 million years

(b) 4.5 billion years

(c) 13 billion years

(d) 100 billion years

(e) the Universe is infinitely old

38. Of the following objects, which one is the youngest?

(a) planet Jupiter

(b) an open star cluster where half the stars are on the Main Sequence

(c) our Sun

(d) a star which just exploded as a massive star Supernova in a very nearby galaxy

(e) a globular star cluster in our Galaxy

39. Spiral arms in galaxies

(a) are the direct result of differential rotation of the disk

(b) are due to spiral density waves propagating through the disk

(c) consist of the same stars at all times

(d) are constantly being wound up by differential rotation

(e) have an unknown origin

40. 21 cm spectral line

(a) is due to cool neutral Hydrogen gas

(b) can be used to study the motion of gas in the disk of the Galaxy

(c) is not affected by dust obscuration

(d) can be detected using radio telescopes

(e) all of the above

41. The rotation curve of our Galaxy

(a) provides direct evidence that Big Bang took place

(b) provides direct evidence that the Galaxy contains unseen matter

(c) is falling rapidly with distance away from the center of the Galaxy

(d) is rising rapidly with distance away from the center of the Galaxy

(e) is very similar in shape to that of the Solar System

42. Galaxy clusters

(a) are hypothetical, and have never been observed

(b) are found mostly near the center of the Universe

(c) are responsible for the Cosmic Microwave Background

(d) do not contain any elliptical galaxies

(e) contain a lot of dark matter

43. Quasars are thought to be

(a) in the process of exploding

(b) very young galaxies

(c) an illusion due to gravitational lensing

(d) objects made of an exotic unknown form of matter

(e) powered by very massive black holes

44. Compared to Spiral galaxies, Elliptical galaxies

(a) have more gas and dust, and more young stars

(b) have more gas and dust, and less young stars

(c) have less gas and dust, and more young stars

(d) have less gas and dust, and less young stars

(e) both types of galaxies have comparable amounts of gas, dust and young stars

45. We know that galaxies contain a large amount of dark matter because

(a) most galaxies look very dark

(b) stars and gas on their outer edges have velocities higher than expected

(c) of the large number of Globular Clusters they contain

(d) galaxies are very old

(e) galaxies are often grouped together into large clusters

46. We can measure the mass of a planet by

(a) applying Kepler's 3rd law to the motion of satellites around the planet

(b) applying Kepler's 3rd law to the motion of the planet around the Sun

(c) applying Kepler's 1st law

(d) counting the number of satellites a planet has

(e) measuring the planet's surface temperature

47. Of the following, what is the most efficient way of converting mass into energy

(a) nuclear fission

(b) nuclear fusion

(c) chemical combustion

(d) dropping matter onto black holes

(e) dropping matter onto white dwarfs

48. Current observations indicate that the Universe

(a) is younger that some of the globular clusters

(b) is older that the Solar System

(c) started to expand soon after the Solar System was formed

(d) will stop expanding after our Sun becomes a Red Giant star

(e) has just reached its minimum size

49. Which one of the following statements is correct?

(a) the edge of the Universe is just beyond the most distant galaxy we can see

(b) the center of the Universe is coincident with the location of the Milky Way

(c) Cosmic Microwave Background Radiation is coming mostly from the direction of Andromeda Galaxy

(d) Hydrogen was produced during Big Bang Nucleosynthesis

(e) none of the above are correct

50. The event in the history of the early Universe that marked the transition between opaque and transparent state was

(a) the Planck era

(b) the Big Bang

(c) nucleosynthesis of Helium and Deuterium

(d) formation of galaxies

(e) production of Cosmic Microwave Background

51. The temperature of the Cosmic Microwave Background

(a) was higher in the past than now

(b) was lower in the past than now

(c) how not changed over time

(d) will continue to increase in the future

(e) has not been measured yet

52. In a negatively curved (open) Universe two parallel beams of light will

(a) stay parallel forever

(b) eventually converge

(c) diverge

(d) get swallowed by a black hole

(e) get absorbed by dark matter

53. The age of the Universe can be determined from

(a) the Hubble law

(b) Newton' laws of motion

(c) the age-luminosity relation of Cepheids

(d) Kepler's 3rd law

(e) conservation of angular momentum

54. Which one of the following distance indicators works at greatest distances?

(a) galaxy brightness

(b) white dwarf Supernova

(c) HR diagram (i.e. Main Sequence fitting)

(d) Cepheids

(e) trigonometric parallax

55. Which of the following statements about Hubble Law of recession of galaxies is incorrect?

(a) Hubble Law can be used to measure the age of the Universe

(b) all distant galaxies are receding from us, while some nearby galaxies are approaching us

(c) velocities of distant galaxies are proportional to their distances away from us

(d) spectra of very distant galaxies show blueshifts

(e) Hubble Law has been shown to be wrong by Hubble's successors

56. The Big Bang refers to the

(a) formation of the Solar System

(b) origin of the heavy elements in Supernova

(c) origin of the Universe

(d) formation of Helium

(e) formation of clusters of galaxies

57. During the epoch of Big Bang Nucleosynthesis the Universe was

(a) similar to the present day Universe in many respects

(b) hot, dense, and opaque

(c) cool and transparent

(d) filled with stars and planets

(e) older than it is today

58. Which one of the following can lead to accelerated expansion of the Universe?

(a) black holes

(b) ordinary matter

(c) dark matter

(d) dark energy

(e) any of the above

59. Which one of the following chemical elements was produced during Big Bang Nucleosynthesis?

(a) Hydrogen              (b) Helium                  (c) Oxygen                  (d) Iron           (e) Uranium

60. What is the geometry of our Universe?

(a) positively curved

(b) negatively curved

(c) flat, i.e. not curved at all

(d) two dimensional

(e) unknown

61. Place the following events in correct chronological order:

Big Bang Nucleosynthesis (BBN), the epoch when Cosmic Microwave

Background was produced (CMB), the formation of galaxies (FG)

(a) CMB, BBN, FG

(b) BBN, FG, CMB

(c) CMB, BBN, FG

(d) BBN, CMB, FG

(e) FG, CMB, BBN

62. The photons of Cosmic Microwave Background

(a) can be detected with optical telescopes

(b) all have the same wavelength

(c) all have the same frequency

(d) have been traveling to us unimpeded for millions of years

(e) are in the X-ray part of the spectrum