Astronomers `spot mega star cradle`

The question of how massive stars form is one of the great conundrums of modern astronomy.

Last Updated: Apr 28, 2010, 14:32 PM IST

Washington: The question of how massive
stars form is one of the great conundrums of modern astronomy.

Now, planetary scientists have caught what they claim could be
the sight of a mega star cradle.

Using "Mopra" radio telescope, an international team,
spotted a massive cloud of mostly hydrogen gas and dust, three
or more light-years across, that is collapsing in on itself
and will probably form a huge cluster of stars.

Dr Stuart Ryder of the Anglo-Australian Observatory
said the discovery was made during a survey of more than 200
gas clouds. "With clouds like this we can test theories of
massive star cluster formation in great detail," he said.

The gas cloud, called BYF73, is about 8,000 light
years away, in the constellation of Carina (the keel) in the
Southern sky.

Evidence for "infalling" gas came from the radio
telescope`s detection of two kinds of molecules in the cloud -
HCO+ and H13CO+. The spectral lines from the HCO+ molecules in
particular showed the gas had a velocity and temperature
pattern that indicated collapse.

The CSIRO telescope observations were confirmed by
observations with Atacama Submillimeter Telescope Experiment
(ATSE) telescope in Chile.

The team has calculated that the gas is falling in at
the rate of about three per cent of the Sun`s mass every year
-- one of the highest rates known.

Follow-up infrared observations made with the 3.9-m
Anglo-Australian Telescope showed signs of massive young stars
that have already formed right at the centre of the gas clump,
and new stars forming.

Gas cloud BYF73 was found during a large-scale search
for massive star-forming regions -- the Census of High and
Medium-mass Protostars, or CHaMP. This is one of the largest,
most uniform and least biased surveys to date of massive
star-forming regions in our Galaxy.

The findings have been published in the `Monthly
Notices of the Royal Astronomical Society` journal.