Spectroscopic Observations of X-Ray Selected Late Type Stars

  • L. O. Takalo
Conference paper
Part of the Astrophysics and Space Science Library book series (ASSL, volume 143)


A spectroscopic survey of 9 X-ray selected late type stars has been conducted. These stars are serendipitiously discovered EINSTEIN X-ray sources, selected from two large X-ray surveys: the Columbia Astrophysical Laboratory survey (5 stars) and the CFA Medium Sensitivity survey (4 stars). Four of the Columbia survey stars were found to be short period binaries (probable RS CVn’s). The fifth Columbia survey star was found to be an active single G dwarf. None of the Medium Sensitivity Survey stars were found to be either binaries or active stars. Activity was measured by comparing the H-alpha and the Call infrared triplet (8498, 8542) lines in these stars to the lines in inactive stars of similar spectral type. A correlation was found between the excess H-alpha line emission and V sin(i) and between the excess H-alpha line emission and X-ray luminosity. No correlation was found between the infrared line emission and any other measured quantity.


Spectroscopic Observation Active Star Late Type Star Excess Emission Spectroscopic Survey 
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Copyright information

© Kluwer Academic Publishers 1988

Authors and Affiliations

  • L. O. Takalo
    • 1
  1. 1.Institute of AstronomyThe Pennsylvania State UniversityCambridgeEngland

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