1) Hints for HW#7:
In problem #2:
Question: I don't know what the picture should
look like?
Answer: Draw a triangle with M31 apparent linear
size as the baseline, and do the trigonometry. You should get the correct
result.
Question #4:
Question: What "formula" should we use?
Thanks!
Answer: You should follow the following
line of inquiry:
I. If we shrunk the andromeda galaxy and placed
it 10pc away from us (same luminosity) what would its magnitude be? (It
will be a negative number because the galaxy would be fairly bright). Box
24.1 in pg 388 of FETU has the expression to help you here.
II. Do we know the magnitude of the sun if it
was placed at that distance?
Now compare I and II. How much brighter is I?
That's how many more stars there are in I! (Use table on the left side
of page 382).
I believe this should be enough hints here.
|
