Astronomers Spot 'Christmas Tree'
Nebula
Tuesday, December 27, 2005
TUCSON, Ariz. Astronomers using NASA's Spitzer Space Telescope
have discovered a perfectly decorated Christmas tree 2,500 light
years from earth.
Scientists at the University of Arizona's Steward Observatory said
the remarkable star cluster gives them the first glimpse of newborn
stars acting just as predicted patterned geometrically and spaced
according to density, temperature and gravity.
"If you look at the very young stars in the cluster and the spacing
between them, it isn't random spacing," said Erick T. Young, an
astronomer at the Steward Observatory. "They're all about the same
distance apart."
The stars are less than 100,000 years old and located in a nebula
in the Monoceros, or Unicorn, constellation. The constellation is
visible in the winter sky to the east of Orion.
The images captured by the space telescope reinforce the basic
theory that the gravity and density of the dust and gas cloud are
determining factors in the formation of stars.
"This is the first really good demonstration that the theory works
on something like a star cluster," Young said.
The observations reinforce British astronomer James Jeans' early
1900s gravitational collapse theory and could yield clues to the
formation of the solar system.
"We believe this process of forming stars in a cluster was exactly
the same thing that happened with our very own sun 4½ billion years
ago," Young said. "It tells us a lot about the history of our own
solar system."
The "Christmas Tree Cluster" is about 1 to 3 million years old and
too young for planets to have formed.
The observations were made a year ago but have just been published
in the Astronomical Journal after a year of research.
The scientists used images collected with a University of
Arizona-built infrared camera and another device on the NASA craft
developed by the Smithsonian Astrophysical Observatory to construct
the images.
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