Brown Dwarf Stars Discovered Clustered Together

Oct 13, 2011, 08:59 by R.E. Christian

Canadian astronomers say they've discovered a cluster of more than two dozen brown dwarf stars, sometimes described as "failed stars," floating free in space.

Brown dwarfs are not quite stars but are more than planets, glowing brightly when young from the heat of formation but cooling down over time, often ending up with atmospheres with planet-like characteristics.

Scientists say they believe most brown dwarfs may have formed like stars in contracting gas clouds, but some of the smallest free-floating examples may have formed like planets around a star and later been ejected.

"Our findings suggest once again that objects not much bigger than Jupiter could form the same way as stars do," University of Toronto astrophysicist Ray Jayawardhana said. "In other words, nature appears to have more than one trick up its sleeve for producing planetary mass objects."

One of the discovered brown dwarfs is one of the least-massive ever observed, astronomers said.

"Its mass is comparable to those of giant planets, yet it doesn't circle a star. How it formed is a mystery," said Aleks Scholz of the Dublin Institute of Advanced Studies in Ireland, formerly a postdoctoral fellow at the University of Toronto.

Source: UPI