SANTIAGO (Reuters) - Theories about how massive stars are born could be revised after astronomers in Chile found evidence that the dust and gas surrounding a young star could survive bombardment by the star’s own radiation.
The Atacama Large Millimeter/submillimeter Array, or ALMA, observed a young star in the constellation of Scorpius that has a mass about 15 times greater than that of the Sun.
A star forms from a collapsing gas cloud. The nascent star attracts more gas and dust due to gravity, gradually creating a spinning “accretion disk” from which planets can be formed. Some of that material is fired off in supersonic jets of gas.
Particularly high mass stars, though, emit ultraviolet radiation in their birth that many astronomers have thought until now would destroy the disk and jets and impede the star’s formation.
However, ALMA, an array of radio telescopes, showed that such radiation can peacefully coexist with gas and dust - the first time such a confirmed observation has been made.
“Many astrophysicists who study star formation thought that these disks and jets couldn’t survive when the star began to emit its ultraviolet radiation, that they would rapidly disperse,” said University of Chile astronomer Andres Guzman Fernandez.
“But here we have found that they not only exist and survive, but that the star continues gaining mass through its accretion disk”.
Expectations of further discoveries by ALMA, situated under the dry, rarefied skies of the Chilean desert, are high. Earlier this month, astronomers using the radio telescope published some of the most detailed images yet seen of early planetary formation around a baby star.
Reporting by Reuters TV, Writing by Rosalba O'Brien; Editing by Steve Orlofsky