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X-ray and optical observations of the ultrashort period dwarf nova SW Ursae Majoris - A likely new DQ Herculis starTime-resolved X-ray and optical photometric and optical spectroscopic observations of the ultrashort period cataclysmic variable SW UMa are reported. The spectroscopic observations reveal the presence of an s-wave component which is almost in phase with the extreme line wings and presumably the white dwarf. This very unusual phasing in conjunction with the available optical and X-ray data seems to indicate that a region of enhanced emission exists on the opposite side of the disk from the expected location of the hot spot. The photometric observations reveal the presence of a hump in the light curve occurring at an orbital phase which is consistent with the phase at which the region of enhanced line emission is most favorably seen. Changes in the hump amplitude are seen from night to night, and a 15.9 min periodicity is evident in the light curve. The optical and X-ray periodicities suggest that SW UMa is a member of the DQ Her class of cataclysmic variables.
Document ID
19870032207
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Shafter, A. W. (McDonald Observatory; Texas, University Austin, United States)
Szkody, P. (Washington, University Seattle, United States)
Thorstensen, J. R. (Dartmouth College Hanover, NH, United States)
Date Acquired
August 13, 2013
Publication Date
September 15, 1986
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 308
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NSF AST-85-00790
CONTRACT_GRANT: NAG8-516
CONTRACT_GRANT: NSF AST-84-05923
Distribution Limits
Public
Copyright
Other