posted on Sep, 26 2011 @ 12:18 PM
Absolute magnitude is a measure of how bright an object is. It's a mathematical way of removing distance from the equation to figure out how bright
something actually is, as opposed to how bright it seems to be based on distance. (like apparent magnitude)
For example, the sun, as everybody knows is massively bright. However, it's quite far away from earth, obviously. Imagine that you had a very bright
light in your room. That light would seem to be brighter than the sun, but only because it's right up in your face. The absolute magnitude of the
sun is higher than that of the light in your room, even though it seems dimmer because it is far away.
Another example would be some of the stars. There are stars that are thousands of times larger and brighter than the sun. However, they are so
distant that they appear only as pinpricks of light in the night sky. The sun has a higher apparent magnitude than any star in the night sky, because
it's so much closer.
The sun does not have a higher absolute magnitude than some of those stars. If you moved the sun and one of those massive stars so that they were
both 10 parsecs away, the massive star would appear to be much brighter than the sun, because it's bigger.
I don't think there's any special meaning to them picking 10 parsecs as the number. They had to pick something as a reference point, and
mathematically it doesn't really matter what they use. They probably just picked an easy to remember number. The number 10 is also easier in
logarithmic calculations, and I think magnitude is measured in logarithmic scales, so that might be why they picked that number; easier math.
edit begins here:
Oh yeah, and with the sun being 4 and elenin being 10, a smaller number means that the object is brighter. The numbers can also go negative as well;
such an object would be hundreds of times or more brighter than the sun.
edit on 26-9-2011 by DragonsDemesne because: (no reason