Figure 1
This infrared image from NASA's Spitzer Space Telescope shows the Rosette
nebula, a pretty star-forming region more than 5,000 light-years away in
the constellation Monoceros. In optical light, the nebula looks like a
rosebud, or the "rosette" adornments that date back to antiquity.
But lurking inside this delicate cosmic rosebud are so-called planetary
"danger zones" (see spheres illustrations in figure 1). These zones surround super hot
stars, called O-stars (blue stars inside spheres), which give off intense
winds and radiation. Young, cooler stars that just happen to reside within
one of these zones are in danger of having their dusty planet-forming
materials stripped away.
While O-star danger zones were known about before, their parameters were
not. Astronomers used Spitzer's infrared vision to survey the extent of
the five danger zones shown here. The results showed that young stars
lying beyond 1.6 light-years, or 10 trillion miles, of any O-stars are
safe, while young stars within this zone are likely to have their
potential planets blasted into space.
Radiation and winds from the super hot stars have collectively blown
layers of dust (green) and gas away, revealing the cavity of cooler dust
(red). The largest two blue stars in this picture are in the foreground,
and not in the nebula itself.
This image shows infrared light captured by Spitzer's infrared array
camera. Light with wavelengths of 24 microns is red; light of 8 microns is
green; and light of 4.5 microns is blue.
