From: Marshall Space Flight Center
Posted: Tuesday, October 14, 2003
Massive stars lead short, yet spectacular lives, as a new multi-wavelength image from NASA's Chandra X-ray Observatory and optical telescopes shows. X-ray (blue) and optical (red and green) data reveal dramatic details of a portion of the Crescent Nebula, a giant gaseous shell of gas created by powerful winds blowing from the doomed massive star HD 192163.
After only 4.5 million years (one-thousandth the age of the Sun), HD 192163 began its headlong rush toward a supernova catastrophe. First, it expanded enormously to become a red giant and ejected its outer layers at about 20,000 miles per hour. Two hundred thousand years later -- a blink of the eye in the life of a normal star -- the intense radiation from the exposed hot, inner layer of the star began pushing gas away at speeds in excess of 3 million miles per hour!
When this high-speed "stellar wind" rammed into the slower red giant wind, a dense shell was formed. In the image, a portion of the shell is shown in red. The force of the collision created two shock waves: one that moved outward from the dense shell to create the green filamentary structure, and one that moved inward to produce a bubble of million-degree Celsius X-ray-emitting gas (blue). The brightest X-ray emission is near the densest part of the compressed shell of gas, indicating that the hot gas is evaporating matter from the shell.
HD 192163 will likely explode as a supernova in about 100,000 years. This image enables astronomers to determine the mass, energy, and composition of the gaseous shell around this pre-supernova star. An understanding of such environments provides important data for interpreting observations of supernovas and their remnants.
The image and additional information are available at:
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