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:
