Birth of a solar system?
The star known as HR 4796 is one of the closest
candidates for possible Earth-like planetary satellites
'Nearby' planet-forming zone spotted
April 21, 1998
Web posted at: 1:42 p.m. EDT (1742 GMT)
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WASHINGTON (CNN) -- Planets like Earth may be forming
elsewhere in the universe, astronomers said on Tuesday,
following the recent discovery of a "young" star that may be
in the process of creating its own solar system.
The star, about 1,320 trillion miles from Earth in the
constellation Centaurus, is surrounded by a vast, rotating
dust cloud, called a "disk." Newborn planets already may
have formed within the disk, said Michael Werner of NASA's
Jet Propulsion Laboratory (JPL) at a Washington news
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Within the disk is an empty region, or hole, that may have
been swept clean when material from the dust cloud was pulled
into newly formed planetary bodies, according to David
Koerner of the JPL, who co-discovered the region.
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"This hole is as large as our entire solar system," he told
reporters. The disk itself is about three times the size of
Pluto's orbit around the sun.
But the scientists said it remains to be seen whether the
forming planets contain ingredients for the emergence of life
or will include planets the size of Jupiter and Saturn, the
largest in our solar system. It was possible, they said, the
disk may consist only of asteroids and comets.
Keck II telescope on Mauna Kea, Hawaii
The star and dust formation could be what our solar system
looked like at the end of its main planetary formation phase,
Koerner called the finding a "missing link" in the study of
how planetary systems are born and evolve.
Scientists released an image of the probable site of planet
formation around the star, known as HR 4796. The image was
taken with a sensitive infrared camera developed at JPL.
HR 4796 is not the first candidate for possible Earth-like
planetary satellites, but it is one of the closest and also
represents a crucial period in planetary evolution.
It may be a youthful cousin of Beta Pictoris, which is also
a good prospect for a solar system like our own. But Beta
Pictoris, whose surrounding dust disk was discovered in 1983,
is about 200 million years old, while HR 4796 is about 10
million, a prime planet-making age.
A Keck II image without the effects of Keck's optics
and added noise shows the large hole in the dust cloud
HR 4796 and the outer disk was spotted by the Keck II
telescope on Mauna Kea, Hawaii, March 16 by astronomers based
at JPL and Franklin and Marshall College in Pennsylvania.
The dust disk was discovered at the same time by another team
at the Cerro Tololo Observatory in Chile. This team included
scientists from the Harvard-Smithsonian Center for
Astrophysics in Massachusetts and the University of Florida
Nature magazine Tuesday published related observations by
astronomers from the Joint Astronomy Center in Hawaii and at
the University of California, Los Angeles, funded by the
National Science Foundation and NASA.
These scientists said their observations of three of the most
well-known stars in the Milky Way -- Vega, Fomalhaut and Beta
Pictoris -- suggested that planets in our galaxy may be more
common than previously believed.
Reuters contributed to this report.