The Unexpected: Normal Stars

Here's our next installation in our occasional series on the Chandra blog called "The Unexpected." These posts will take a look at some of the biggest surprises (and expected discoveries) made by Chandra so far in its mission. Today's topic is "normal stars," which is what astronomers call stars that are similar to our Sun.

Expected and Detected:
X-ray emission from the outer atmospheres, or coronas, of stars of almost every type: young and old, large and small.

Unexpected: Detection of X-ray flares from brown dwarfs, or failed stars. This discovery provides a new way to study how the magnetic field changes on low-mass stars as they age.

More information:
http://www.chandra.harvard.edu/photo/2006/w3/

Unexpected: Chandra observations of massive stars suggest that some of these stars may not be losing nearly as much mass in strong winds flowing away from the stars as previously thought.

Unexpected: Radiation from a single massive star has triggered the formation of hundreds of new stars.

More information:
http://www.chandra.harvard.edu/photo/2009/cepb/

Unexpected: Flares from very young stars are much more fre- quent and intense than on the present-day Sun, and may actually aid the formation of planets around these stars.

More information:
http://www.chandra.harvard.edu/photo/2005/orion/

Unexpected: Evidence that the X-ray emitting hot gas from planetary nebulas comes from deep within a Sun-like star that has neared the end of its evolution and will soon become a white dwarf.

More information:
http://chandra.harvard.edu/photo/2006/pne/

To read more on Chandra and normal stars, visit our Field Guide on this topic at
http://www.chandra.harvard.edu/xray_sources/normal_stars.html