1. The primary distances to the stars are found by
e) parallax (Triangulation by observing from different points
in the Earth's orbit.)
2. The parallax of a star is 0.01 seconds of arc. What is its
distance?
d) 100 pc (Distance in parsecs = 1/parallax
3. What is the color of a star with a temperature of 3000 K?
e) red
4. What characterizes the spectrum of an A star?
b) strong hydrogen
5. What characterizes the spectrum of an M star?
a) titanium oxide
6. Of those spectral classes below, the hottest is
d) B (Only O stars are hotter.)
7. The Sun has what absolute magnitude and is of what spectral
class?
c) +5, G2
8. A class F dwarf star is typically made mostly of
e) hydrogen
9. The standard spectral sequence is a result of
a) different stellar temperatures
10. The most luminous dwarf stars below are of class
a) O
11. The most common stars are
e) M, L, and T dwarfs
12. White dwarfs are typically about the size of
c) Earth
13. We know that supergiants are really larger than giants because
supergiants
b) are brighter than giants that have the same
temperatures
14. Stellar masses are found from
b) double stars
15. As you go down the main sequence from class A, stellar
masses
b) decrease
16. What is the minimum mass for a star that will run full hydrogen
fusion (in solar units)?
c) 0.08
17. The masses of white dwarfs are similar to that of
d) the Sun
18. The coolest and brightest M supergiants are about at big as the
orbit of
d) Jupiter or Saturn
19. Open clusters are found in the
a) Milky Way (the disk of our Galaxy)
20. Brown dwarfs are
a) stars below the proton-proton chain mass cutoff
21. The spectra of class T stars are characterized by
a) methane
22. Globular clusters are
e) all of the above (found in the Galaxy's halo, much more massive
than open clusters, are the oldest objects known, are much
rarer than open clusters)
23. Old star clusters are missing
b) their upper main sequences (since high mass stars die
first)
24. How old are the oldest star clusters in billions of years?
d) 12
25. The classic case of a white dwarf is the companion to
d) Sirius