•
Question 8 (1 point) You
observe two stars with the same absolute
magnitude and determine spectroscopically that one is type B star while the other is a type G star. What
can you conclude about the
sizes of the stars?
a.Nothing. b.The G star is larger than the B star. c.The B star is larger than the G star. d.The stars are the
same size.
•L
is equal for the two stars, so (TG/TB)4(RG/RB)2 must equal one. The temperature of the G star is cooler
than that of a B star, so the first term must be less than one. There for the other term must be greater than one. This is also clear from looking at
lines of constant
radius on an HR diagram, that a G star would have to be a giant to have as much luminosity as a B
star.
• Question
9 (1 point) A 3 solar mass star on the main sequence would have a luminosity how many times larger than
the sun's?
a.3 b.9 c.47d.94 e.1000
•Just
some math here. L = M3.5, and 33.5=47.