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Steve Roy
Marshall Space Flight Center, Huntsville, AL
Phone: 256-544-6535

Megan Watzke
Chandra X-ray Observatory Center, CfA, Cambridge, MA
Phone: 617-496-7998

Science Contacts:
Sangwook Park, park{at}astro.psu.edu, 814-863-7111

May 26, 2003

CXC Press Release: 05-02

Chandra Finds Rich Oxygen Supply Inside Glowing Ring

Scientists using NASA's Chandra X-ray Observatory have detected large 
amounts of oxygen and other elements in the remnant of a star that 
exploded in a nearby galaxy. For years scientists have known that the 
elements necessary for life are created in massive stars and
dispersed in supernova explosions, but the process has rarely been
caught "on camera." 

The Chandra image of supernova remnant, SNR 0103-72.6, shows a
striking, nearly perfect ring about 150 light years in diameter
surrounding a cloud of gas enriched in heavy elements and shock
heated to millions of degrees Celsius. The ring marks the outer
limits of a shock wave produced as material ejected in the supernova
explosion plows into the interstellar gas. The size of the ring
indicates that we see the supernova remnant as it was about 10,000
years after its progenitor star exploded.

According to Dr. Sangwook Park of Penn State University in University 
Park, lead author of a presentation today at the meeting of the
American Astronomical Society in Nashville, Tenn., "Hundreds of
supernova remnants are scattered throughout our galactic
neighborhood, but we detect only a handful rich in oxygen. This
Chandra image is a rare treat." 

Oxygen is synthesized by nuclear reactions in the interiors of stars
at least ten times as massive as the Sun. When such a star explodes,
its core collapses to form either a neutron star, or if massive
enough, a black hole, and the material surrounding the core is
propelled into interstellar space.

"The most abundant elements in this remnant are oxygen and neon,"
Park said. "Their location near the center of the remnant is evidence
that the progenitor star was at least ten times as massive as the
Sun." 

SNR 0103-72.6 is located in the Small Magellanic Cloud (SMC) about 
190,000 light years from Earth. The X-rays take about 190,000 years
to reach us from the SMC, so the supernova explosion occurred about
200,000 years ago, as measured on Earth. One of the closest galaxies
to the Milky Way galaxy, the SMC is visible to the naked eye from the
Southern Hemisphere.

"This supernova remnant will become a laboratory for studying how
stars forge the elements necessary for life," said Park. Although SNR
0103-72.6 is more distant than supernova remnants in our Galaxy, 
scientists have a clear view of it because its light is not blocked
by the dusty spiral arms of the Milky Way.

Other members of the team involved in this observation are David 
Burrrows, John Nousek and Gordon Garmire of Penn State; John Hughes
of Rutgers University in Piscataway, N.J., and Patrick Slane of the
Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.
Garmire is the principal investigator on this observation.

The ACIS instrument was built for NASA by Penn State and the 
Massachusetts Institute of Technology under the leadership of
Garmire. NASA's Marshall Space Flight Center manages the Chandra
program, and TRW, Inc., Redondo Beach, Calif., is the prime
contractor for the spacecraft. The Smithsonian's Chandra X-ray Center
controls science and flight operations from Cambridge, Mass., for the
Office of Space Science at NASA Headquarters, Washington.

The image and additional information are available at:

     http://chandra.harvard.edu/photo/2003/snr0103/
and
     http://chandra.nasa.gov

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