Posted by sam on .
An astronomer observes two galaxies, A and B, which have redshifts of:
Galaxy A = 0.020 and Galaxy B = 0.010.
Which galaxy is closest to us and what is its distance away from us?
You may assume that the Hubble constant is H0 = 75 km s–1 Mpc−1 and that the speed of light is
c = 3.0 × 105 km s–1.
The closest galaxy is: Galaxy a?? or galaxy b??
It is at a distance of ????? Mpc.?
Assuming that Galaxy A is intrinsically of identical luminosity to Galaxy B, how does its apparent brightness on the night sky compare to that of Galaxy B?
Galaxy A is ???? times BRIGHTER or FAINTER??? than Galaxy B.