Stars, Galaxies, and The Universe - Lecture notes - Astro 6 PDF

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Quiz 3

1. The object displayed above is A) an elliptical galaxy B) an open star cluster C) a globular star cluster D) an irregular galaxy E) a cluster of galaxies Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): B

2. Which is youngest? A) the Sun B) a G star high above the Galactic plane C) a metal-poor K star D) a Cepheid variable E) an RR Lyr star Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): D

3. Our Sun A) is located within a star-forming region in one of our Galaxy's spiral arms. B) is located near the center of our Galaxy. C) is located within an open cluster. D) is located in the halo of our Galaxy. E) is located in our Galaxy's disk, but just outside a spiral arm. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

4. In which type of galaxy would you expect to find the most supernovae? A) an Sb galaxy B) an elliptical galaxy C) an SBa galaxy D) an S0 galaxy E) an Sc galaxy Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

5.

The Local Group is what we call A) a nearby collection of globular clusters. B) the nearest open cluster. C) the small group of galaxies to which our Milky Way galaxy belongs. D) the nearest large cluster of galaxies. E) a small collection of G-stars near the Sun. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): C

6. An knowledge of the absolute luminosity of RR Lyr stars comes from A) measurements of RR Lyrae stars in open clusters. B) observations of RR Lyrae stars near the Galactic center. C) observations of RR Lyrae stars in other galaxies. D) parallax measurements of RR Lyrae stars. E) measurements of RR Lyrae stars in globular clusters of known distance. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

7. The above object is

A) an E1 galaxy B) an Sc galaxy C) an irregular galaxy D) SBb galaxy E) an Sa galaxy Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): B

8. Which has the shortest lifetime? A) a white dwarf B) a B main sequence star C) a G main sequence star D) a K main sequence star E) an F main sequence star Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): B

9. We believe that the dark matter of a spiral galaxy A) is in a spherical halo that extends far beyond the disk of the galaxy. B) orbits the galaxy's central black hole. C) is located in the galaxy's star clusters.

D) is confined to the galaxy's disk, but not restricted to the spiral arms. E) is located in the galaxy's spiral arms. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

10. The galaxies of the Local Group are mostly A) very small and irregular. B) medium-sized Sc galaxies. C) medium-sized barred spirals. D) medium-sized galaxies that are colliding with one another. E) large and elliptical. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

11. Quasars are most likely located A) in open clusters. B) in globular clusters. C) in the centers of distant galaxies. D) between the galaxies of rich clusters. E) in the halos of nearby galaxies. Table for Individual Question Feedback

Points Earned: 0.0/1.0 Correct Answer(s): C

12. The spiral arms of the galaxy M51 appear blue, but its central bulge is red. This is because A) the spiral arms contain many young stars. B) the central bulge contains many emission nebulae (H II regions). C) the spiral arms contain many Population II stars. D) the spiral arms are approaching us and are blue-shifted. E) the light from the central bulge is reddened by interstellar dust. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): A

13. Stars which enter the instability strip A) begin to rotate very rapidly. B) implode. C) lose much of their mass. D) pulsate. E) explode. Table for Individual Question Feedback Points Earned: 1.0/1.0

Correct Answer(s): D

14. The image above is that of A) a barred spiral galaxy. B) an Sc spiral galaxy. C) an open cluster. D) two galaxies colliding. E) a star-forming region. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): D

15. A standard candle is A) any object whose Doppler shift is known. B) any object that always has the same apparent magnitude. C) any object whose absolute luminosity is known. D) any object whose absolute luminosity changes with time. E) any object whose parallax is known. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): C

16. H II regions A) are usually found between the arms of spiral galaxies. B) are present in all types of galaxies. C) are often found around metal-poor stars. D) are regions of gas ionized by O and B main sequence stars. E) are extremely cold regions of interstellar gas and dust. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): D

17. Most of the mass in a spiral galaxy A) is in some form of matter that we know nothing about. B) is within stars. C) is in the form of molecular gas. D) is in the form of atomic hydrogen. E) resides within a big black hole. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

18. The stars of a globular cluster A) are old and metal-poor. B) are young and metal-rich.

C) are old and metal-rich. D) are young and metal-poor. E) have a range of ages and metallicities. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

19. Halo stars A) are generally rich in metals. B) are often obscured by foreground dust. C) generally orbit in random directions. D) are usually called A stars. E) generally all orbit in the same direction. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): C

20. Gravitational lenses A) prove that black holes exist. B) magnify the brightnesses of nearby stars. C) turn red light into blue light. D) are useful for estimating the masses of galaxy clusters. E) can be used to measure the brightnesses of distant quasars. Table for Individual Question Feedback

Points Earned: 1.0/1.0 Correct Answer(s): D

21. Which of the following statements about elliptical galaxies is not true? A) Elliptical galaxies have little, if any, star formation. B) Elliptical galaxies usually appear red. C) Elliptical galaxies are often found near the centers of galaxy clusters. D) Elliptical galaxies often have black holes at their center. E) Elliptical galaxies are usually smaller than spiral galaxies. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

22. Quasars A) are roughly the size of our Solar System. B) are roughly the size of a globular cluster. C) are roughly the size of a galaxy cluster. D) are roughly the size of a dwarf galaxy. E) are roughly the size of a Milky Way-type galaxy. Table for Individual Question Feedback Points Earned: 0.0/1.0

Correct Answer(s): A

23. Most supernovae observed in spiral galaxies are located A) in the spiral arms, since that's where the massive O main sequence stars are located. B) near the center of the galaxy, since that's the region with the highest density of stars. C) between the spiral arms, since that's where typical stars like the Sun reside. D) far in the galaxy's halo, since supernovae are easiest to observe when they're far from the galactic center. E) inside globular clusters, since globular clusters contain the oldest stars. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

24. Which can be observed at the greatest distance? A) a Milky Way-type galaxy B) a quasar C) an RR Lyr star D) the Sun E) an O main sequence star Table for Individual Question Feedback Points Earned: 1.0/1.0

Correct Answer(s): B

25. In the distant past, our Galaxy A) had more metals than it does today. B) had more stars than it does today. C) was an elliptical galaxy. D) had a bigger black hole than it does today. E) had less mass than it does today. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

26. The nearest supermassive black hole is A) at the center of the closest radio galaxy, 3.5 Mpc away. B) at the center of the M4 globular cluster, 2 kpc away. C) at the center of the Andromeda galaxy, 750 kpc away. D) at the center of the Milky Way galaxy, 7.5 kpc away. E) at the center of the closest quasar, 750 Mpc away. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): D

27. If you look in the direction of the plane of our Galaxy, you will not see A) emission from molecules, such as carbon monoxide. B) open star clusters. C) H II regions. D) 21 cm emission from neutral hydrogen gas. E) many other galaxies. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

28. An active galactic nucleus creates its energy via A) the nuclear fusion of hydrogen. B) stellar collisions. C) gravitational contraction. D) accretion onto a compact object. E) radioactive decay. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): D

29. Identify the cluster (if possible) A. Cluster a

B. Cluster b C. Cluster c D. Cluster d E. Impossible to tell ABCDEThe oldest cluster ABCDEThe nearest cluster ABCDEThe cluster with the highest mass stars Table for Individual Question Feedback Points Earned: 2.0/3.0 Correct Answer(s): Cluster c:The oldest cluster, Cluster b:The nearest cluster, Cluster b:The cluster with the highest mass stars

30. If we measure the amount of metals in the atmosphere of a star to be much larger than that in the Sun, we can conclude that A) the star is on the main sequence. B) the star is an extreme Population I object. C) the star is very old. D) the star will soon go supernova. E) the star is a red giant and is burning helium to carbon and oxygen in its core. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): B

31.

When a dwarf galaxy comes close to the Milky Way, A) it will cause the Milky Way to be tidally distorted, while the dwarf galaxy itself will remain largely unaffected. B) both galaxies will be distorted, but will rapidly return to their originally shape. C) it will cause the Milky Way to be tidally distorted, and the dwarf galaxy will be ripped to shreds. D) it will pass right through, and both galaxies will be unaffected by the event. E) it will be ripped to shreds, while the Milky Way will remain largely unaffected. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

32. Match the type of light to the object which emits it. (You may use the same wavelength more than once.) A. radio waves B. infrared light C. optical light D. x-rays E. ultraviolet light ABCDEH II regions ABCDEinterstellar atomic hydrogen ABCDEcarbon monoxide in molecular clouds ABCDEprotostars ABCDEsupermassive black hole Table for Individual Question Feedback Points Earned: 4.0/5.0

Correct Answer(s): optical light:H II regions, radio waves:interstellar atomic hydrogen, radio waves:carbon monoxide in molecular clouds, infrared light:protostars, xrays:supermassive black hole

33. Collisions between two spiral galaxies A) often create large amounts of star formation. B) cause many stars to collide, thus creating supernovae. C) create bigger spiral galaxies. D) form large black holes. E) almost never happen. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

34. One of the reasons we believe dark matter exists is that A) dark matter explains the shapes of elliptical galaxies. B) the rotation curves of spiral galaxies are flat in their outer regions. C) dark matter explains the shapes of spiral arms. D) elliptical galaxies are often found in galaxy clusters. E) dark matter explains how galaxies first formed. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s):

B

35. Harlow Shapley used the distances to globular clusters to A) discover that our Galaxy has spiral arms. B) measure the distance to the center of the Galaxy. C) measure the distance to the nearest star-forming region. D) discover the existence of metal-poor stars. E) measure the brightnesses of RR Lyrae stars. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): B

36. Which statement about AGN is not true. A) Most AGN have emission lines. B) Most AGN are x-ray sources. C) Most AGN are variable. D) Many AGN have radio jets. E) Most AGN are in galaxy clusters. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

37.

We believe that most galaxies contain supermassive black holes in their center. The best evidence for this comes from the fact that the centers of most galaxies A) emit no light at all. B) act as a gravitational lens. C) are observed to have jets. D) emit x-rays. E) have stars orbiting at very high velocities. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): E

38. Molecular clouds A) are usually found far above and below the Galactic plane. B) are the coldest and densest phase of the interstellar medium. C) are called H II regions. D) can only be detected with ultraviolet telescopes. E) contain very little hydrogen. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): B

39. The Milky Way's disk probably formed A) from the accretion of an elliptical galaxy. B) from the collision of two smaller galaxies.

C) from a large, flat dust cloud. D) from the particles ejected by a quasar. E) from a very slowly rotating, roughly spherical cloud of gas. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

40. Globular clusters A) contain more metal-poor stars than open clusters. B) are less massive than open clusters. C) contain more Cepheids than open clusters. D) contain more B main-sequence stars than open clusters. E) are found mostly in the disk of our Galaxy. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

41. The image above show a A) an open cluster. B) a field of stars in the Milky Way. C) a star-formation region. D) a globular cluster. E) a cluster of galaxies.

Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): E

42. The Hubble type of the Milky Way is probably A) SBa B) E7 C) E0 D) Sb E) SBc Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

43. Most of the bright blue stars in the Milky Way galaxy A) are in globular clusters. B) are near the Galactic Center. C) are in the Galaxy's spiral arms. D) are in the spheroidal component (the halo) of our Galaxy. E) are in the disk of the Galaxy, between the spiral arms. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s):

C

44. Astronomers have difficulty studying the center of the Milky Way Galaxy because A) there is a lot of dust between us and the Galactic Center. B) our Sun is moving around the Galaxy too fast for us to get a good view. C) there are too many H II regions between us and the Galactic Center. D) the density of stars near the Galactic Center is too high to make out any detail. E) there are too many stars between us and the Galactic Center. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): A

Quiz 2 Map Submitted by ROSS-ROBERTSON, COREY (CPR5132) on 10/24/2014 5:12:46 PM

Points Aw Awarded arded 41.00 Points Missed 9.00 Percentage 82.0%

1. The object above is A) planetary nebula. B) an H II region. C) the result of a supernova explosion. D) the result of a nova explosion. E) a protostellar gas cloud. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

2. Match the star to the letter in the above diagram. Note that the same letter can be used more than once.

A. Star 1 B. Star 2 C. Star 3 D. Star 4 E. Star 5 F. Star 6 ABCDEFthe ABCDEFthe ABCDEFthe ABCDEFthe ABCDEFthe ABCDEFthe ABCDEFthe

star star star star star star star

which is hottest which is least luminous which is smallest in radius which has the weakest gravity at its surface which is most evolved which is most like the Sun with the least amount of hydrogen

ABCDEFthe star which is definitely greater than 1.5 solar masses ABCDEFthe star with a core of pure helium ABCDEFthe star with the strongest hydrogen absorption in its spectrum Table for Individual Question Feedback Points Earned: 7.0/10.0 Correct Answer(s): Star 1:the star which is hottest, Star 3:the star which is least luminous, Star 5:the star which is smallest in radius, Star 4:the star which has the weakest gravity at its surface, Star 5:the star which is most evolved, Star 2:the star which is most like the Sun, Star 5:the star with the least amount of hydrogen, Star 1:the star which is definitely greater than 1.5 solar masses, Star 4:the star with a core of pure helium, Star 6:the star with the strongest hydrogen absorption in its spectrum

3. Deneb has strong hydrogen absorption in its spectrum. Alnitak has weaker hydrogen lines, but strong helium lines. From this, we can conclude that A) Deneb and Alnitak have different temperatures. B) Deneb and Alnitak have different apparent magnitudes. C) Deneb and Alnitak have different absolute luminosities. D) Deneb is less evolved than Alnitak. E) Deneb and Alnitak have different masses. Table for Individual Question Feedback Points Earned: 0.0/1.0 Correct Answer(s): A

4. When will the Sun become a nova? A) When the Sun's core turns to iron

B) When the Sun's core turns to helium C) When the Sun's core turns to carbon D) Just after the Sun becomes a planetary nebula. E) The Sun will never go nova. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): E

5. Which element is most abundant in a K main-sequence star? A) hydrogen B) helium C) carbon D) calcium E) iron Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

6. The nickel in this coin was formed A) in a supernova explosion. B) in a nova explosion. C) in the center of the Sun. D) in a planetary nebula. E) in a star-forming region.

Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

7. The Sun's energy comes from A) the fusion of hydrogen to helium. B) the fusion of helium to carbon and oxygen. C) the nuclear fission of heavy elements. D) slow gravitational contraction. E) chemical reactions in its center. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

8. Binary stars (i.e., two stars orbiting each other) are A) very common, and useful for measuring stellar masses. B) postulated to exist, but none are actually known. C) relatively common, and useful for measuring stellar luminosities. D) somewhat common, and useful for measuring stellar temperatures. E) exceedingly rare; only a few binary stars are known. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s):

A

9. Stars spend most of the lives A) on the main sequence. B) as red giants. C) as helium-burning stars. D) in the planetary nebula phase. E) burning iron in their core. Table for Individual Question Feedback Points Earned: 1.0/1.0 Correct Answer(s): A

10. Which of these stars may someday become a black hole? A) Sirius B, a 0.98 solar mass white dwarf. B) BD+30 3639, a 0.6 solar mass central star of a planetary nebula. C) the Sun D) 10 Lacertae, ...