Three times as many stars? (new estimate by van Dokkum and Conroy)

[marcus]

The technical paper (published in Nature):
http://arxiv.org/pdf/1009.5992v1

The NYT journalistic account:
http://www.nytimes.com/2010/12/02/science/space/02star.html?_r=1&ref=science

==quote==
How Many Stars? Three Times as Many as We Thought, Report Says
By KENNETH CHANG
Published: December 1, 2010

...Scientists said Wednesday that the number of stars in the universe had been seriously undercounted, and they estimated that there could be three times as many stars out there as had been thought...
==endquote==

Basically, van Dokkum and Conroy used spectroscopy to revise the estimated number of low mass dim stars in a sample of eight elliptical galaxies.

Only about 2/3 of galaxies are pinwheel-shaped spirals, like the Milkyway. There are also large blob-shaped galaxies called ellipticals that account for a substantial fraction of existing stars.

The authors found that low-mass stars (less than 1/3 the mass of the sun) are about 10-times more abundant in the elliptical galaxies they studied, than had earlier been assumed based on their abundance in the Milkyway.

 

[TrickyDicky]

It looks like an interesting finding, in some journalistic accounts like http://www.universetoday.com/80955/red-dwarf-discovery-changes-everything/ they are stressing the consequences on the amount of Dark Matter this would have. It would decrease the proportion a little, certainly would not eliminate the mass deficit, not even if something similar happened with brown dwarfs as some are saying. But it would only have to change a bit the proportion of DM wrt baryonic matter to make look the current "precision cosmology" results from the CMB power spectrum not so precise after all.