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a new method to determine the interstellar reddening towards wn starsAn empirical approach to determine the redding in WN stars is presented, in which the measured strengths of the emission lines of He II at 1640 and 4686 A are used to estimate the extinction. The He II emission lines at these wavelengths are compared for a number of WN stars in the Galaxy and the LMC. It is shown that the equivalent width ratios are single valued and are independent of the spectral subtypes. The reddening for stars in the Galaxy is derived using a Galactic extinction law and observed line flux ratios, showing good agreement with previous determinations of reddening. The possible application of the method to study the absorption properties of the interstellar medium in more distant galaxies is discussed.
Document ID
19900039540
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Conti, Peter S.
(Joint Inst. for Lab. Astrophysics Boulder, CO, United States)
Morris, Patrick W.
(Joint Institute for Laboratory Astrophysics Boulder, CO, United States)
Date Acquired
August 14, 2013
Publication Date
March 1, 1990
Publication Information
Publication: Astronomical Journal
Volume: 99
ISSN: 0004-6256
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAG5-1016
CONTRACT_GRANT: NSF AST-88-06594
Distribution Limits
Public
Copyright
Other