Why are astronomers much more interested in the luminosity of a star than its apparent brightness?

Question

Please help!

Answer 1

Because apparent brightness is just how it appears to us here on Earth. It's a combination of the star's distance from us and it's intrinsic brightness. (i.e., a flashlight two inches from your eyes can appear much larger and brighter than a bigger flashlight 500 feet away).

Luminosity gives much more information about the star.

Answer 2

Apparent brightness is determined by two factors, the luminosity of the star and its distance from us. Luminosity means more in terms of the star's properties. For example, the Sun has a tremendous apparent brightness; so much that only the moon and, on occassion Venus, can be seen in the daytime. The sun is also just 150x106 km distant. Yet, when the sun is compared to other stars in terms of luminousity, it is really a "run-of-the-mill" star.

Answer 3

Apparent brightness depends on the star's luminosity AND its distance from us.
So an apparently dim star could still be much more luminous than a closer star.

Luminosity is a function of the size, temperature, and chemical content of the star, so that provides much more information about the star than apparent brightness does.

Answer 4

I think luminosity is like finger print for human. It clearly identifies a star with lot of details like its temparature, distance from us, its internal contents etc

Scince is always about finding more accurate things, instead of satisfying with what seems accurate. Since luminosity gives more accurate things than apparent brightness astronomers are more interested in luminosity