A Massive Star and Its Cradle

The picture shows a massive star, located in a distant cloud of gas and cosmic dust. It was acquired by NASA’s infrared space-based observatory, the Spitzer Space Telescope. 

Credit: ESO/NASA/JPL-Caltech/S. Kraus

Astronomers caught their first insights of a disk containing cosmic dust around a massive newly born star, yielding direct evidence that massive stars form in the same way as the low mass stars. Combined data, from the ground-based European Southern Observatory (ESO) and NASA's infrared space-based observatory, the Spitzer Space Telescope (SST), led to this intriguing discovery.

"Astronomers have long been unclear about how the most massive stars form," said Stefan Kraus, astronomer at the University of Michigan. "Because they tend to be at very large distances, and surrounded by dusty envelopes, it's very hard to separate and closely observe them."

To get a closer view, the team applied ESO's Very Large Telescope Interferometer (VLTI), a giant sophisticated system of four large telescopes, whose light-grasping power is equivalent to a single telescope of 85-meter aperture, to study an object technically designated IRAS 13481-6124. About twenty times more massive than our Sun, and five times larger in diameter, the young central star, which is still surrounded by a cloud of dust and gas, is located in the constellation Centaurus, about 10,000 light years away.

"We were able to get a very sharp view into the innermost regions around this star by combining the light from separate telescopes," Kraus said, "basically mimicking the resolving power of a telescope with an incredible 85 meter-wide mirror."

Thanks to this unique technology, the team's observations detected a massive disk of dust and gas around the giant young star. "This is the first time that something like this has been observed," said Kraus. "The disk very much resembles what we see around young stars that are much smaller, except everything is scaled up and more massive".

The discovery of this disk is a strong evidence that like the low mass stars, the largest stars in the Galaxy are formed due to the collapse of huge clouds of dust and gas, rather than from the merging of smaller stars, as postulated earlier by some scientists. The confirmation of this came from the Spitzer Space Telescope data archive, which contains the 26.5 million images that have been acquired during Spitzer's mission so far.

Further Reading

Unravelling the Mystery of Star Birth - Dust Disk Discovered Around Massive Star

http://www.spitzer.caltech.edu/news/1153-feature10-11-Unravelling-the-Mystery-of-Star-Birth-Dust-Disk-Discovered-Around-Massive-Star

Aymen Mohamed Ibrahem
Senior Astronomy Specialist