AY 101-051                                                      Summer 2011 
                                   QUIZ #5

1.  If we look at star clusters of greater and greater ages, we see that
   A) THE BRIGHTEST REMAINING MAIN-SEQUENCE STARS ARE PROGRESSIVELY LOWER IN MASs.
   b) there are fewer and fewer red giants.
   c) there are progressively more of the hot stars at the top of the main sequence.
   d) there are fewer red dwarfs.

2. To measure a star's distance using parallax, we measure
   a) its luminosity.
   b) its apparent size.
   c) changes in its Doppler shift.
   D) ITS POSITION IN THE SKY AT DIFFERENT TIMES OF THE YEAR. 

3. The solar cycle is associated with periodic changes in the Sun's
   a) neutrino emission. 	      		c) diameter.
   B) MAGNETIC FIELD.            	       	d) fusion rate.

4. We can measure the masses of which kinds of stars?
   a) red giants.                                c) white dwarfs.
   B) BINARY.                                    d) M-type.

5.  In the Hertzsprung-Russell (HR) diagram, the Sun is located as
   A) A MAIN-SEQUENCE STAR.                            c) a red giant.
   b) a white dwarf.                                          d) a supergiant.

6. To determine a star’s luminosity, we need to know its
   A) BRIGHTNESS AND DISTANCE.		c) diameter and brightness
   b) temperature and brightness.	d) size and distance.

7. The net effect of processes in the sun's core is to
   A) START WITH HYDROGEN AND TRANSFORM IT INTO HELIUM.
   b) start with helium and transform it into hydrogen.
   c) start with hydrogen and transform it into iron.
   d) start with iron and transform it into hydrogen.

8. Confirmation of nuclear processes in the Sun comes from measuring
   a) gamma rays.    		c) its magnetic field.
   B) NEUTRINOS.                       	d) solar flares.

9. Sunspots are a side effect of
   a) changes in the rate of energy production within the Sun.
   B) LOOPS IN THE SUN'S MAGNETIC FIELD.
   c) solar neutrinos.
   d) the planets' gravitational pull.

10. All main-sequence stars produce energy by
A)	FUSING HYDROGEN TO HELIUM IN THE CORE.
b)	fusing hydrogen to helium throughout the star.
c)	fusing helium to carbon in the core.
d)	a reaction between oxygen and hydrogen, releasing he