Celestia Forums

I'm familiar with the general numerical breakdown of star by spectral type - that most stars (about 70-80% of all stars) are M, and progressively less are the hotter, more massive types. (as shown by that 'pyramid of stars' where most of it is red, then as you get near the top you get smaller and smaller slices of orange (K), yellow (G), Yellow-white (F), and White (A) etc).

But one thing I have no handle on at all is the proportion of stars out there that are White Dwarfs. I'm guessing that it's less than 10% of all stars, since obviously late G, and K and M V stars won't have had time to become white dwarfs yet given the age of the galaxy (13.6 Ga or thereabouts). But does anyone actually have any estimates based on observational data? Can anyone point me to some research on this?

(note that I'm not interested in outright guesses or peoples' opinions here. I'm looking for some hard data on this)

And now just to answer my own question , I did find this paper:
http://arxiv.org/abs/astro-ph/0102120

Apparently there are 51 WDs within a 13pc volume around the sun, and the authors think this number represents all the ones that are there. According to Sol Station ,there are about 22 WDs in a 10 pc volume around Sol, at least 250 M V stars within a 10pc volume around Sol (it's likely that this number is not the complete census of all M V stars - let's guess it's 350 really, based on what RECONS says) , and 74 AFGK V stars in the same volume Sol.

So there's 22 out of 424 stars in a 10 pc around Sol that are WDs, which is about 5.2%... hm. Interesting... I'm assuming that's about normal for our region of space?

I have read around 9% of the stars in the galaxy are white dwarfs. Of course that is based on selective data.

Still, that's in about the right ball park...