Chandra spectroscopy of the hot star β Crucis and the discovery of a pre-main-sequence companion

  title={Chandra spectroscopy of the hot star $\beta$ Crucis and the discovery of a pre-main-sequence companion},
  author={David H Cohen and Michael A. Kuhn and M. Gagn'e and E. L. N. Jensen and Nathan A. Miller Swarthmore College currently at Penn Sta Wisconsin and Eau Claire},
  journal={Monthly Notices of the Royal Astronomical Society},
In order to test the O star wind-shock scenario for X-ray production in less luminous stars with weaker winds, we made a pointed 74-ks observation of the nearby early B giant, β Crucis (β Cru; B0.5 III), with the Chandra High Energy Transmission Grating Spectrometer. We find that the X-ray spectrum is quite soft, with a dominant thermal component near 3 million K, and that the emission lines are resolved but quite narrow, with half widths of 150 km s -1 . The forbidden-to-intercombination line… 
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