Star a and b have the same luminosity, but star b is 10 times farther from earth than star a. how much brighter will star a appear?

100 times brighter

Explanation:

The apparent luminosity of a star follows the inverse square law, which means that the luminosity is inversely proportional to the square of the distance:

where r is the distance.

In this problem, star A and star B have same intrinsec luminosity, but star B is 10 times farther than star A:

We can write the luminosity of star A as follows:

While the luminosity of star B will be:

Substituting :

So, star A will appear 100 times brighter than star B.

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