Credit: A. J. J. Raassen et al., 2003, Astronomy & Astrophysics, vol. 402, pp. 653-666
Wolf-Rayet stars are believed to be evolved, massive stars and the precursors of
supernovae. They are rather mysterious since they are shrouded by a thick wind
which constantly blows from the star into interstellar space, keeping
astronomers from directly viewing the stellar surface. Much is hidden by the WR
star's wind, and astronomers still do not have a clear understanding of basic
stellar parameters like size and temperature despite nearly 150 years of study.
Sensitive new X-ray observatories like Chandra and XMM-Newton are helping
astronomers understand these objects by probing the X-ray emission from these
stars. The image above left shows what is thought to be a "young" Wolf-Rayet star, WR
25, in the Carina Nebula, as seen by the X-ray cameras on XMM-Newton. WR 25 is
one of the brightest X-ray emitting WR stars known and is the bright source at the center of this false-color image. On the right is an overlay of the X-ray contours on an optical image of the region, showing emission from WR 25 and other sources, like WR 25's famous neighbor
Eta Carinae. The new XMM-Newton
observations show surprisingly high temperature emission (near 30 million degrees) from this star. These observations and other earlier ones suggest that WR 25 may in fact have a hidden companion nearby.
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Page Author: Dr. Michael F. Corcoran
Last modified Friday, 20-Apr-2012 15:27:17 EDT