By Ron Cowen
There are more dim bulbs in the universe than even the most hardened pessimist might have imagined.
Astronomers who examined eight relatively nearby galaxies have found evidence of a surprisingly high abundance of faint, low-mass stars — each has about 10 times as many as the Milky Way. Those elderly galaxies are so chock-full of faint stars that the researchers extrapolate that the heavens contain up to three times the total number of stars previously estimated.
The profusion of stars also suggests that the early history of the cosmos may need a rewrite, perhaps doubling previous estimates of the total mass of stars in many of the universe’s first, massive galaxies. If so, those early galaxies would have forged stars at a much more prodigious rate, says Pieter van Dokkum of Yale University. He and Charlie Conroy of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., describe their study in a paper appearing online in Nature on December 1.