• Question
7 (1 point) The location of the sun relative to the center of our
galaxy was FIRST CORRECTLY
determined by
a.the relative brightness of the visible
Milky Way in different directions. b. the positions of the globular clusters and the properties of the
variable stars in them. c.the position of supernova. d.radio
maps of the galaxy.
Question 8 (1 point) Which of the
following would you not expect to find in the Population II halo?
a.B star b.red
dwarf c.neutron star d.white dwarf
•Because B stars must be young stars, and there is no
new star formation in the halo.
•
•Question 9 (1 point) The black hole in
the center of our Milky Way galaxy seems to be about 2.6 million times the mass of the sun. What
is the radius of its event horizon?
Think about how big this is compared to other astronomical objects (e.g., Earth, the sun, the solar system, the distances
between stars).
a.About a billion km. b.About 4
thousand km. c.About 4 million km. d.About 8 thousand km. e. About 8 million km.
•Easy way. 1
solar mass Schwarzschild radius is 3km, so 3x2.6 million is 8 million km.
•
• Question
10 (1 point) One fundamental requirement for an object to be a
good tracer (i.e. marker)
of the galaxy's spiral arms is that it be
a.moving with small radial velocity (relative
to earth). b.moving with large radial velocity (relative to earth). c. a short lived and therefore young
object. d. a very long lived and therefore probably old object.