ASTR 2003   Test 3   6/15/99

1. The outermost layer of the Sun is its  (a) radiative zone  
  (b) convective zone  (c) chromosphere  (d) corona  (e) halo.

2.The Sun's core contains less hydrogen than its photosphere.  (a) true  
  (b) false

3. Sunspots look darker than surrounding photosphere because they  
  (a) are less magnetic  (b) have strong electric fields  (c) are more 
  turbulent  (d) are cooler.

4. At sunspot maximum, most spots are at _______ solar latitudes.  
  (a) low  (b) medium  (c) high  (d) mis-leading; there is no such pattern

5. Trapped solar wind particle produce  (a) coronal holes  (b) flares  
  (c) aurorae  (d) thunderstorms.

6. Solar granulation is a visible manifestation of  (a) radiative heat 
  transport  (b) conductive heat transport  (c) convective heat 
  transport  (d) none of these.

7. The proton-proton cycle converts protons into  (a) electrons  
  (b) lithium  (c) carbon  (d) helium.

8. Due to _______ effects, Hubble Space Telescope images are somewhat 
  blurred.  (a) "seeing"  (b) absorptive  (c) slewing  (d) diffraction.

9. A star of magnitude 5 is _______ than one of magnitude 0.  
  (a) 10 times fainter  (b) 10 times brighter  (c) 100 times fainter  
  (d) 100 times brighter

10. 10 parsecs is about _____ Light Years.  (a) 5  (b) 20  (c) 26  
   (d) 33  (e) 100

11. Is a star of spectral type G8 hotter or cooler than the Sun?  
   (a) hotter  (b) cooler  (c) could be either one

12. The Sun is a  (a) giant  (b) supergiant  (c) white dwarf  
   (d) main sequence star.

13. A star the same color as the Sun but more luminous than the Sun 
   must also be  (a) more massive  (b) older  (c) younger  (d) larger.

14. A hot, low density gas produces  (a) absorption lines  (b) emission 
   lines  (c) a continuum  (d) double lines.

15. The Doppler shift increases with the _______ of the star.  
   (a) temperature  (b) density  (c) transverse velocity  (d) radial 
   velocity

16. A graph of stars' absolute magnitude and color index is a  
   (a) Kirchoff plot  (b) Hertzsprung-Russell diagram  (c) Hubble chart 
   (d) radial velocity diagram.

17. A star the same color as the Sun, but 50 times as large as the Sun 
   would be a  (a) massive main sequence star  (b) giant  
   (c) supergiant  (d) blue straggler.

18. A star the same color as the Sun, but the size of the Earth would 
   be a  (a) white dwarf  (b) pygmy star  (c) neutron star  
   (d) planetary nebula.

19. Which star is largest?  (a) red supergiant  (b) blue supergiant  
   (c) ultraviolet supergiant

20. If you pick a star in the solar neighborhood at random, it will 
   most likely be a  (a) white dwarf  (b) neutron star  (c) red giant  
   (d) main sequence star.

21. Red giants generate ______ in their cores.  (a) helium  (b) carbon  
   (c) iron  (d) uranium

22. The Sun will die as a  (a) white dwarf  (b) neutron star  
   (c) supernova  (d) black hole.

23. Interstellar gas clouds that begin collapsing are likely to be 
   ___________.  (a) cool and dense  (b) cool and tenuous  
   (c) hot and dense  (d) hot and tenuous.

24. We can sometimes penetrate a dusty cocoon nebula in the _________
    part of the spectrum.  (a) X-ray  (b) ultraviolet  (c) infrared  
   (d) gamma-ray.

25. A low-mass pre-main-sequence star first appears in the region of 
   the __________.  	(a) white dwarfs  (b) red giants  
   (c) blue supergiants  (d) substars.

26. T Tauri variable stars are ___________.  (a) pre-main-sequence 
   objects  (b) post-main-sequence objects  (c) main-sequence objects  
   (d) white dwarfs

27. Bipolar flows are associated with  (a) pre-main-sequence objects  
   (b) post-main-sequence objects  (c) main-sequence objects  
   (d) white dwarfs.

28. In very young star clusters, the _________ stars are still 
   pre-main-sequence objects.  (a) reddest  (b) bluest  (c) most massive 
   (d) hottest

29.A forming object less massive than 0.08 solar masses is bound to 
   become a  (a) brown dwarf  (b) white dwarf  (c) neutron star  
   (d) supernova.

30. What fraction of the core of a main-sequence star is hydrogen at 
   the end of its main-sequence lifetime?  (a) 0  (b) 1/2  (c) 3/4  
   (d) 90%

31. Horizontal-branch stars are  (a) pre-main-sequence objects  
   (b) post-main-sequence objects  (c) main-sequence objects  
   (d) white dwarfs.

32. Near the end of its luminous lifetime, the Sun will go through a 
   ____________ stage.  (a) supernova  (b) supergiant  (c) brown dwarf  
   (d) planetary nebula

33. The Sun will eventually become a  (a) brown dwarf  (b) white dwarf  
   (c) neutron star  (d) supernova.

34. A radio pulsar is a kind of  (a) brown dwarf  (b) white dwarf  
   (c) neutron star  (d) supernova.

35. The Sun will one day become a supernova.  (a) true  (b) false

36. A famous supernova remnant is the  (a) ring nebula, M57  
   (b) dumbbell nebula, M27  (c) Crab nebula, M1  (d) great nebula in 
   Andromeda, M31.

37. Blue skies and red sunsets are due to  (a) interstellar dust  
   (b) interference  (c) diffraction  (d) Rayleigh scattering.

38. Stars whose light is highly polarized will look __________ than 
   expected.  (a) redder  (b) brighter  (c) more massive  (d) bigger

39. HI regions are associated with  (a) star birth  (b) star death  
   (c) post-main-sequence evolution  (d) explosions.

40. The 21-cm line is associated with  (a) interstellar dust  
   (b) intersellar gas  (c) supernova explosions  (d) planetary nebulae.

41. HII regions glow because of  (a) very hot stars  (b) inductive 
   heating  (c) electric currents  (d) turbulence.

42. Where does the iron in your blood come from?  (a) planetary nebulae  
   (b) the core of the Sun  (c) HII regions  (d) supernovae

43. Single stars like the Sun are the most common.  (a) true  (b) false

44. A ________ binary star has a long orbital period.  (a) spectroscopic 
   (b) eclipsing  (c) close  (d) wide

45. Stellar ______ can only be determined from studies of binary stars. 
   (a) masses  (b) radii  (c) luminosities  (d) spin rates

46.The presence of the _____________ leads to mass transfer in close 
   binary stars.  (a) barycentre  (b) Lagrangian surface  (c) Hubble 
   flow  (d) Chandraeskar Limit

47. In both the Sirius problem and the Algol paradox, the least massive c
   omponent is the  (a) white dwarf  (b) red giant  (c) neutron star  
   (d) most evolved star.

48. Mass transfer onto a neutron star leads to a supernova explosion.  
   (a) true  (b) false - white dwarf  (c) false - main-sequence star

49. Newly discovered extrasolar planets were discovered with the 
   __________ technique.  (a) transverse motion  (b) radial velocity  
   (c) astrometric  (d) occultation

50. Wide binary stars are formed by  (a) fusion  (b) fission  
   (c) capture  (d) co-accretion.