Massive stars lead short, spectacular lives (Forwarded)

Steve Roy
Media Relations Dept.
Marshall Space Flight Center, Huntsville, AL

(256) 544-0034

Megan Watzke
Chandra X-ray Observatory Center, CFA, Cambridge, MA

(617) 496-7998

For release: 10/14/03

Photo release no.: 03-184

Massive stars lead short, spectacular lives
[http://www1.msfc.nasa.gov/NEWSROOM/n...os03-184.html]

Massive stars lead short, spectacular lives. This composite image -- X-ray shown
in blue and optical shown in red and green -- reveals dramatic details of a
portion of the Crescent Nebula, a giant gaseous shell of gas created by powerful
winds blowing from the 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, shown
in blue, in an image from NASA's Chandra X-ray Observatory. 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 a hundred thousand 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.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra
program.

Credits: X-ray: NASA/UIUC/Y. Chu & R. Gruendel; Optical: SDSU/MLO/Y. Chu et al.