By Ron Cowen
Before a star can be born, gas and dust from a cold interstellar cloud must gather together into a distinct clump. Astronomers say they have now witnessed this earliest of steps in the star-birthing process.
French scientists used a radio telescope to home in on emissions from a dark, dusty cloud of material in the Taurus star-forming region some 400 light-years from Earth. By mapping dust emission from the cloud along with two chemical tracers of density, the researchers found that the cloud has begun to detach from its surroundings and contract. In addition, the density at the cloud’s center is higher than that at its outer edge, the team found.
“This is the discovery of a cloud at the really beginning of the star formation process, with a new star expected in about 1 million years,” says study member Laurent Pagani of the Observatoire de Paris. He and his colleagues posted their findings online December 8.