APOD: A Horseshoe Einstein Ring from Hubble (2011 Dec 21)

Comments and questions about the APOD on the main view screen.
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Re: APOD: A Horseshoe Einstein Ring from Hubble (2011 Dec 21

Post by zloq » Fri Dec 23, 2011 5:01 pm

Ann wrote: A third reason for the claim that the Sun is an average star is that its mass is indeed "midway" between the most massive and the least massive of the stars in our galaxy.

I think that is all that is meant by the sun being "average" - just that it falls in the middle of the range of parameters of known stars. This means it is not meant as an average over the known population of stars which, as you say, is ill-defined because the small, faint ones are hard to see and count. Plus - the relative population depends on where you are in a galaxy - or in other galaxies. So it is just in the middle of the range, and the actual average over stars in our galaxy would be heavily skewed by the vastly more numerous small, faint ones.