why is there a distinction made between apparent magnitude and absolute magnitude?

Question

thanx

Answer 1

Well, sometimes a star can be the brightest thing in space. Just not on earth. Apparent magnitude is what WE on earth can see. Absolute magnitude is the real brightness a star gives. Sometimes, looks can be decieving =D Good luck to ya =D

Answer 2

Absolute magnitude measures how bright a star would appear if they were all at the same distance from earth. Sort of like leveling the playing field. Using absolute magnitude means we don't have to consider distance as a reason the star is bright or dim.
Apparent magnitude measures how easily we can see the star in the sky - a star can be bright because its close, or just bright, or both. Apparent magnitude doesn't tell us why its bright.

Answer 3

Basically, absolute is how bright the star really is. Apparent is how bright it looks from whatever distance you are seeing it. Just like a streetlight looks small and dim if it is 10 miles away, but is really bright close up, so with stars. Absolute magnitude is kind of like the wattage of the star, while apparent magnitude is how bright it appears to you.

Absolute magnitude is how bright it would look if it were exactly 10 parsecs away. If it really is 10 parsecs away it will look that bright, but if it is closer it will look brighter. And if it is farther away it will look dimmer. One parsec is about 3.2 light years. It is actually defined as 206,265 AU, where one AU is the distance from the Earth to the Sun. Sounds strange, but there is a good reason. It corresponds to a heliocentric parallax of one arc second.

Answer 4

apparent magnitude is how bright the star looks from earth.

Absolute magnitude is how bright the star would be if it was 10 parsecs away (32.6 light years).

BY calculating the absolute magnitude astronomers can compare that star to other stars in a way that keeps them all equal, so that you can truly compare the brightnesses of different stars.