February 11, 2009

Physicists show how stellar jets develop

U.S. and British astrophysicists say they have conducted the first laboratory experiment that accurately models stellar jets and explains how they form.

Astrophysicists say they have long been at a loss to explain how the jets of matter streaming from stars achieve their varied shapes.

The predominant theory says that jets are essentially fire hoses that shoot out matter in a steady stream, and the stream breaks up as it collides with gas and dust in space, but that doesn't appear to be so after all, said University of Rochester Professor Adam Frank, co-author of the research, who said experiments strongly suggest the jets are fired out more like bullets or buckshot. They don't break into pieces -- they are formed in pieces, he said.

Frank said the experiment, conducted with Imperial College of London Professor Sergey Lebedev, might be the best astrophysical experiment that's ever been done.

The complex research showing how magnetic forces shape stellar jets is reported in the journal Astrophysical Review Letters.