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RCW 38:
Young Star Cluster Found Aglow With Mysterious X-Ray Cloud
At a distance of 6,000 light years from Earth, the star cluster RCW 38 is a relatively close star-forming region. This image covers an area about 5 light years
across, and contains thousands of hot, very young stars
formed less than a million years ago. X-rays from the
hot upper atmospheres of 190 of these stars were
detected by Chandra.
In addition to the point-like emission from stars, the
Chandra image revealed a diffuse cloud of X-rays
enveloping the star cluster. The X-ray spectrum of the
cloud shows an excess of high-energy X-rays, which
indicates that the X-rays come from trillion-volt
electrons moving in a magnetic field. Such particles
are typically produced by exploding stars, or in the
strong magnetic fields around neutron stars or black
holes, none of which is evident in RCW 38.
One possible origin for the high-energy electrons is an
undetected supernova that occurred in the cluster.
Although direct evidence for such a supernova could
have faded away thousands of years ago, a shock wave or
a rapidly rotating neutron star produced by the
outburst could be acting in concert with particles
evaporating off the young stars to produce the high
energy electrons.
Regardless of the origin of the energetic electrons,
their presence could change the chemistry of the disks
that will eventually form planets around stars in the
cluster. For example, in our own solar system, we find
evidence of certain short-lived radioactive nuclei
(Aluminum 26 being the most well known). This implies
the existence of a high-energy process late in the
evolution of our solar system. If our solar system was
immersed for a time in a sea of energetic particles,
this could explain the rare nuclides present in
meteorites found on Earth today.
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Fast Facts for RCW
38:
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Credit
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NASA/CXC/CfA/S.Wolk et al.
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Scale
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Image is 8.1 arcmin on a side.
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Category
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Normal Stars & Star Clusters
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Coordinates
(J2000)
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RA 08h 59m 19.2s | Dec -47º 30'
22" |
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Constellation
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Vela
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Observation
Date
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December 10, 2001
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Observation
Time
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27.2 hours
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Obs.
ID
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2556
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Color
Code
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Energy: Red (low), Green (medium),
Blue (high)
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Instrument
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ACIS
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Distance
Estimate
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About 6,000 light years
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Release Date
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December 18, 2002
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