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Comparative pulsation calculations with OP and OPAL opacitiesComparative linear nonadiabatic pulsation calculations are presented using the OPAL and Opacity Project opacities. The two sets of opacities include effects due to intermediate coupling and fine structure as well as new abundances. We used two mass luminosity (M-L) relations, one standard (BIT), and one employing substantial convective core overshoot (COV). The two sets of opacities cannot be differentiated on the basis of the stellar pulsation calculations presented here. The BIT relation can model the beat and bump Cepheids with masses between 4 and 7 solar mass, while if the overshoot relation is used, masses between 2 and 6 solar mass are required. In the RR Lyrae regime, we find the inferred masses of globular cluster RRd stars to be little influenced by the choice of OPAL or OP. Finally, the limited modeling we have done is not able to constrain the Cepheid M-L relation based upon period ratios observed in the beat and bump stars.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Kanbur, Shashi M.
(Univ. of Nebraska-Lincoln, Lincoln, NE United States)
Simon, Norman R.
(Univ. of Nebraska-Lincoln, Lincoln, NE United States)
Date Acquired
August 16, 2013
Publication Date
January 10, 1994
Publication Information
Publication: The Astrophysical Journal, Part 1
Volume: 420
Issue: 2
ISSN: 0004-637X
Subject Category
Accession Number
Funding Number(s)
Distribution Limits

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