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Outer atmospheres of cool stars. XIII - Capella at critical phasesThe results are presented of a program of high-dispersion spectroscopy of Capella at critical orbital phases utilizing the International Ultraviolet Explorer. The considered program had the objective to establish as carefully as possible the relative ultraviolet emission levels of the Capella primary and secondary in order to obtain an understanding regarding the nature of their chromospheres and coronae. The results of the program confirm the earlier study of the Capella by Ayres and Linsky (1980), which was limited to orbital phases 0.50 and 0.75. Both programs found that the Capella secondary is considerably brighter than the primary, in surface flux, in all of the prominent far-ultraviolet emissions, particularly the high-excitation CII-CIV lines. In addition, the present study has revealed several puzzling aspects of the system. It is concluded that the Capella primary is comparatively bright, for a yellow giant, in far-ultraviolet and perhaps also in soft X-ray normalized fluxes. The implications of this conclusion are evaluated.
Document ID
19830064335
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Ayres, T. R.
(Colorado, University Boulder, CO, United States)
Schiffer, F. H., III
(Computer Sciences Corp. Astronomy Dept., Silver Spring, MD, United States)
Linsky, J. L.
(Joint Institute for Laboratory Astrophysics Boulder, CO, United States)
Date Acquired
August 11, 2013
Publication Date
September 1, 1983
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 272
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
83A45553
Funding Number(s)
CONTRACT_GRANT: NAG8-2
CONTRACT_GRANT: NAS5-26409
CONTRACT_GRANT: NAG5-199
CONTRACT_GRANT: NGL-06-003-057
Distribution Limits
Public
Copyright
Other

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