Cheers.
The stars in a star cluster are all approximately
the same distance from us. If you
compare two stars in a cluster and notice
that one is brighter than the other, does this
mean that it is necessarily more luminous?
Explain.
Is this answer a yes? Since they are the same distance away from the earth, one of them has to have a higher surface temperature or size to appear more luminous. I would not necessarily be more luminous if they were different distances apart.