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Author Stothers, Richard B.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ CONVECTION ♦ MASS ♦ OSCILLATIONS ♦ RADIAL VELOCITY ♦ VARIABLE STARS ♦ ENERGY TRANSFER ♦ HEAT TRANSFER ♦ MASS TRANSFER ♦ STARS ♦ VELOCITY
Abstract Giant convection cells in the envelopes of massive red supergiants turn over in a time comparable in order of magnitude with the observed long secondary periods in these stars, according to a theory proposed some years ago by Stothers and Leung. This idea is developed further here by using improved theoretical data, especially a more accurate convective mixing length and a simple calculation of the expected radial-velocity variations at the stellar surface. The theory is applied to the two best-observed red supergiants, Betelgeuse and Antares, with more success than in the earlier study. The theory can also explain the long secondary periods seen in the low-mass red giants, thus providing a uniform and coherent picture for all of the semiregular red variables. How the turnover of a giant convection cell might account for the observed slow light and radial-velocity variations, their relative phasing, and the absence of these variations in certain stars is discussed here in a qualitative way, but follows naturally from the theory.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-12-10
Publisher Place United States
Journal Astrophysical Journal
Volume Number 725
Issue Number 1


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