MessageToEagle.com - NASA's Swift satellite has uncovered the previously unknown remains of a shattered star.
Designated G306.3–0.9 after the coordinates of its sky position, the new object ranks among the youngest-known
supernova remnants in our Milky Way galaxy.
"Astronomers have previously cataloged more than 300 supernova remnants in the galaxy," said lead scientist
Mark Reynolds, a postdoctoral researcher at the University of Michigan in Ann Arbor.
"Our analysis indicates that G306.3–0.9 is likely less than 2,500 years old, making it one of the 20 youngest
Click on image to enlarge
This composite of supernova remnant G306.3–0.9 merges Chandra X-ray observations (blue), infrared data acquired by the Spitzer Space Telescope (red and cyan) and radio observations (purple) from the Australia Telescope Compact Array. The image is 20 arcminutes across, which corresponds to 150 light-years at the remnant's estimated distance.
Credit: X-ray: NASA/CXC/Univ. of Michigan/M. Reynolds et al; Infrared: NASA/JPL-Caltech; Radio: CSIRO/ATNF/ATCA
Astronomers estimate that a supernova explosion occurs once or twice a century in the Milky Way.
The expanding blast wave and hot stellar debris slowly dissipate over hundreds of thousands of years, eventually
mixing with and becoming indistinguishable from interstellar gas.
Like fresh evidence at a crime scene, young supernova remnants give astronomers the best opportunity for
understanding the nature of the original star and the details of its demise.
Supernova remnants emit energy across the electromagnetic spectrum, from radio to gamma rays, and important
clues can be found in each energy band.
X-ray observations figure prominently in revealing the motion of the expanding debris, its chemical
content, and its interaction with the interstellar environment, but supernova remnants fade out in X-ray
light after 10,000 years and only half of those known in the Milky Way galaxy have been detected in X-rays at all.
Reynolds leads the Swift Galactic Plane Survey, a project to image a two-degree-wide strip along the Milky Way's
central plane at X-ray and ultraviolet energies at the same time. Imaging began in 2011 and is expected to
complete this summer.
"The Swift survey leverages infrared imaging previously compiled by NASA’s Spitzer Space Telescope and extends it
into higher energies," said team member Michael Siegel, a research associate at the Swift Mission Operations Center
(MOC) in State College, Pa., which is operated by Penn State University.
Click on image to enlarge
A wider view places G306.3–0.9 in context with star-formation regions in southern Centaurus. Chandra X-ray observations (blue), Spitzer infrared data (red, cyan), and radio observations (purple) from the Australia Telescope Compact Array are merged in this composite. The image is one degree across, which corresponds to 450 light-years
at the remnant's estimated distance. Credit: X-ray: NASA/CXC/Univ. of Michigan/M. Reynolds et al; Infrared:
NASA/JPL-Caltech; Radio: CSIRO/ATNF/ATCA
"The infrared and X-ray surveys complement each other because light at these energies penetrates dust clouds
in the galactic plane, while the ultraviolet is largely extinguished."
Using an estimated distance of 26,000 light-years for G306.3–0.9, the scientists determined that the explosion’s
shock wave is racing through space at about 1.5 million mph (2.4 million km/h).
The Chandra observations reveal the presence of iron, neon, silicon and sulfur at temperatures exceeding
50 million degrees F (28 million C), a reminder not only of the energies involved but of the role supernovae
play in seeding the galaxy with heavy elements produced in the hearts of massive stars.
"We don’t yet have enough information to determine what type of supernova this was and therefore what type of
star exploded, but we’ve planned a further Chandra observation to improve the picture,” said coauthor Jamie
Kennea, also a researcher at the Swift MOC. "We see no compelling evidence that the explosion formed a neutron
star, and this is something we hope can be determined one way or the other by future work."