Embryo of a star seen for first time

Press, 25 July 1986, Page 25

Embryo of a star seen for first time

NZPA-Reuter Los Angeles

The embryonic stage of a star’s development has been observed for the first time by a team of five astronomers using a radio telescope in Arizona, one of the astronomers said.

“People have been looking for something like this for many years but this is the first time that this process has been observed by astronomers,” said Erick Young, associate astronomer with the Steward Observatory at the University of Arizona at Tucson.

“What we have actually witnessed is the formation process of a star, the embryo stage. The birth process is a very long and drawn-out affair,” he said. “It probably won’t emerge from the cloud that it is forming from for another 109,000 years.” Using the radio telescope at the National

Radio Astronomy Laboratory at Kitt Peak near Tucson, Young said he and colleagues spent 18 months making observations before they were confident enough to announce their findings.

“We measure the motion (of the embryonic star mass) in very much the same way that a police radar gun can measure the speed of a car,” Mr Young said. Called IRAS 1629, for the Infrared Astronomical Satellite that first discovered the object in 1983 and its equatorial co-ordi-nates in the sky, Mr Young said the gaseous mass was slowly collapsing into a small core that has a mass about onetenth that of the Sun.

The discovery, located about 520 light years from Earth (one light year is roughly six thousand billion miles), was important because stars were being formed in the Milky Way

galaxy all the time and every star had gone through the same process at some point in its past, including the Sun, Mr Young said. “Before this particular object was discovered no direct evidence of this fairly important stage in the history of star had been seen,” he said. He said IRAS 1629 was the youngest such mass known and the only one that actually showed a mass being collected from a cloud. He explained that matter in the cloud collapses into a core because of gravity.

The team of astronomers included four from the University of Arizona — Mr Young, Christopher Walker, Charles Lada and Philip Maloney — and one from the University of Missouri, Bruce Wilking. Mr Young said their findings had been accepted for publication in October by the “Astrophysical Journal.”