Star maker

(Photograph) - Star maker: scientists have discovered a new stage in the formation of a star, writes Julia Hinde.

Derek Ward-Thompson of the Royal Observatory in Edinburgh told a meeting of The Royal Astronomical Society that preliminary results from the Infrared Space Observatory (ISO), showed that previous models of star formation were over simplistic in ignoring an early stage in star growth. Working with researchers at Cambridge and in France, Dr Ward-Thompson is using the ISO satellite launched by the European Space Agency in November 1995 to measure the temperature of proto-stars.

He says that this, along with ground-based measurements of the brightness of early stars, can be used to estimate the mass and therefore the rate of star formation. He said: "The model which has been taken as more or less read for the past 20 years is that in which a star accretes material at some steady speed until it gets to a final mass. What our work shows is that a star accretes most of its mass very quickly in the early stages of formation, in the first 10,000 years, and then slows as it forms over the next 100,000 years."

The Edinburgh work will be officially reported next week at the International Astronomical Union meeting in Chamonix, France.