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Einstein Observatory magnitude-limited X-ray survey of late-type giant and supergiant starsResults are presented of an extensive X-ray survey of 380 giant and supergiant stars of spectral types from F to M, carried out with the Einstein Observatory. It was found that the observed F giants or subgiants (slightly evolved stars with a mass M less than about 2 solar masses) are X-ray emitters at the same level of main-sequence stars of similar spectral type. The G giants show a range of emissions more than 3 orders of magnitude wide; some single G giants exist with X-ray luminosities comparable to RS CVn systems, while some nearby large G giants have upper limits on the X-ray emission below typical solar values. The K giants have an observed X-ray emission level significantly lower than F and F giants. None of the 29 M giants were detected, except for one spectroscopic binary.
Document ID
19900033247
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Maggio, A. (Osservatorio Astrofisico Palermo, Italy)
Vaiana, G. S. (Osservatorio Astronomico Palermo, Italy)
Haisch, B. M. (Osservatorio Astrofisico Palermo, Italy)
Stern, R. A. (Lockheed Research Laboratories Palo Alto, CA, United States)
Bookbinder, J. (Joint Institute for Laboratory Astrophysics, Boulder, CO; Smithsonian Astrophysical Observatory, Cambridge MA, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1990
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 348
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NASA ORDER H-89765-B
CONTRACT_GRANT: NAGW-1716
CONTRACT_GRANT: NAGW-112
CONTRACT_GRANT: NAS8-30751
Distribution Limits
Public
Copyright
Other