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Some Remarks on the Unique Cepheid HR 7308

Published online by Cambridge University Press:  12 April 2016

N. R. Simon
N. R. Simon*
Affiliation:
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588-0111

Extract

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HR 7308 is an apparently normal Pop. I Cepheid (Percy & Evans 1980; van Genderen 1981) with a constant period P = 1.49 days. However, its amplitude is variable with a range from about 5 to 20 km/sec in radial velocity and 0.05 to 0.30 in visual magnitude. The timescale for this variation is about 1200 days. According to Breger (1981) and Burki, et al. (1982; hereafter BMB), the star seems to be pulsating in a single modulated radial mode. Using published 0-values BMB identify this mode as a second or higher overtone. These authors also estimate a radius R = 34 ± 5 Rʘ and, based in part upon the observations of van Genderen (1981), a temperature log Te = 3.786 ± 0.01 and a gravity log g = 2.25 ± 0.25.

Type
Part I. Fundamental Parameters
Information
International Astronomical Union Colloquium , Volume 82: Cepheids: Theory and Observations , 1985 , pp. 93 - 94
Copyright
Copyright © Cambridge University Press 1985

References

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