X rays trace fierce stellar winds.

The powerful winds blown out by massive stars carry an enormous amount of energy into space, but astronomers have lacked the tools for tracking the fate of that energy.

Now, a high-resolution X-ray view of the Rosette nebula, a nearby star-forming region, has revealed for the first time that stellar winds heat surrounding gas to a scorching 6 million kelvins. The hot gas emits a diffuse glow of X rays, which the orbiting Chandra X-ray Observatory has detected.

The findings suggest that in stellar nurseries, winds from massive stars collide, creating shock waves that fire up the temperature of the surrounding gas. Leisa K. Townsley of Pennsylvania State University in State College and her colleagues presented the findings Sept. 5 at a symposium in Washington, D.C.

The hot gas lies at the center of the Rosette nebula. At the nebula's core lie a handful of its most massive stars, which emit the strong winds that the astronomers propose are heating the gas.

Studies with other telescopes couldn't easily distinguish specific sources of X rays from the diffuse glow in the nebula. With Chandra, Townsley and her collaborators imaged more than 300 individual stars. Subtracting the contribution of the stars from the overall X-ray view, the researchers confirmed that the stellar winds fuel the nebula's diffuse X-ray glow.