Heidi Sagerud

Physics News posted 7/1/09 | 0 comments

Astronomers Size Up a Candidate for Midsize Black Hole

Black holes vary greatly in size, from relatively small ones several times the mass of the sun, which are born of collapsed stars, to supermassive lurkers like the one at the center of our Milky Way Galaxy, with the mass of about four million suns.

But medium-size black holes—those with hundreds or thousands of times the mass of the sun—have proved an elusive quarry. A study in this week's Nature identifies a new candidate for this seemingly rare third class about 300 million light-years away in the spiral galaxy ESO 243-49. (Scientific American is part of the Nature Publishing Group.)

If confirmed, the midsize black hole and others like it could provide clues to how their supermassive brethren form, which could, in turn, inform how galaxies like ours developed. [more]