Giant Space Cloud Holds Clues to Massive Star Birth
This mid-infrared image of the interstellar cloud BYF 73 from NASA's Spitzer Space Telescope reveals yellowish wisps to the right are remnants of gas that have been heated and are being driven off by the massive young stars within them (seen in blue). The large-scale collapse of colder gas to form a massive cluster is centered around the bright stars just to the left of the heated wisps. <a href=>Full Story</a>.

A vast interstellar cloud has been caught in the act of building huge stars that would dwarf our own sun, giving scientists a tantalizing glimpse into how such massive stars form.

The cloud, called BYF 73, was discovered using the CSIRO Mopra radio telescope in Australia. Made up mostly of hydrogen and dust, the cloud sits about 8,000 light-years from Earth in the Carina constellation.

?At first glance, it is huge ? stretching up to 4 light-years across ? but is collapsing in on itself at one of the fastest speeds ever seen, astronomers said.

Some massive stars, more than 10 times the mass of the Earth's sun, have already been spotted in the newfound cloud in follow-up observations by other telescopes.

But the new observations also spotted something perhaps more significant: More matter is leftover in the cloud than in the giant new stars, suggesting that an entire cluster of massive stars is in the works.

?This means we have a very rare chance to study the formation of an entire cluster from a very early stage,? astronomer Peter Barnes, a study team member from the University of Florida, told

The research, a collaboration of American and Australian astronomers, is detailed in a recent issue of the Monthly Notices of the Royal Astronomical Society.

Astronomers have a good handle on how regular stars form, but the evolution of massive stars has proven hard to decipher because they can be difficult to find and observe.

Most tend to be located in deep space, more than 1,000 light-years away, in populations making up only a few percent of all stars,? Barnes said.

The interstellar cloud BYF 73 is one of nearly 200 clouds observed during a survey that mapped such objects across our Milky Way galaxy.

Later this year, astronomers plan to use the Compact Array telescope in Australia to study the cloud in more detail to better measure the amount of collapsing gas. They will also use the Gemini South telescope in Chile to hunt for stars hidden in the cloud's dust that can't be seen by the Anglo-Australian Telescope in Australia.

?With clouds like this we can test theories of massive star cluster formation in great detail,? said astronomer Stuart Ryder of the Anglo-Australian Observatory.?