Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-19T03:30:01.061Z Has data issue: false hasContentIssue false
  • English
  • Français

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

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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

Aikawa, T. & Simon, N. R. (1983). Ap. J., 273, 346.10.1086/161373CrossRefGoogle Scholar
Breger, M. (1981). Ap. J., 249, 666.10.1086/159327CrossRefGoogle Scholar
Burki, G., Mayor, M. & Benz, W. (1982). Astr. and Ap. 109, 258 (BMB).Google Scholar
King, D. S., Cox, J. P., Eilers, D. D. & Davey, W. R. (1973). Ap. J. 182, 859.10.1086/152189CrossRefGoogle Scholar
Percy, J. R. & Evans, N. R. (1980). A. J. 85, 1509.10.1086/112827CrossRefGoogle Scholar
Simon, N. R. (1984). Ap. J., in press.Google Scholar
Simon, N. R. & Lee, A. S. (1981). Ap. J., 248, 291.10.1086/159153CrossRefGoogle Scholar
van Genderen, A. M. (1981). Astr. and Ap. 99, 386.Google Scholar