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A New Temperature Determination for Sirius B from IUE: Implications for the Observed Soft X-Ray Fluxes

Published online by Cambridge University Press:  12 April 2016

K. Kidder
Lunar and Planetary Laboratory, University of Arizona Tucson, Arizona85721
J.B. Holberg
Lunar and Planetary Laboratory, University of Arizona Tucson, Arizona85721
F. Wesemael
Département de Physique and Observatoire du Mont MéganticUniversitéde Montréal


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We have used IUE archive observations to obtain a new and independent estimate of the effective temperature of Sirius B. In this effort we have modeled the observed Lyman alpha profile of Sirius B as a function of effective temperature and find; Teff = 24,500 ± 500 K. This temperature is in good agreement with a recent result obtained from analysis of EXOSAT soft X-ray spectra of Sirius B. In addition to providing confirmation of the soft X-ray result, this temperature implies that Sirius B is significantly cooler and larger in radius than most previous estimates. The radius, R = 0.090 ± 0.005 R, implied by the lower temperature is well in excess of the radius of fully degenerate star having the mass of Sirius B. This investigation employed a unique set of SWP archive spectra, acquired with Sirius B in the small aperture, which have proved to be free of scattered light contamination from Sirius A.

Research Article
Copyright © Springer-Verlag 1989


Böhm-tense, E., Dettmann, T., and Kaprandis, S.: 1979, Astrophys. J. (Letters), 232, L189.CrossRefGoogle Scholar
Gatewood, G.D., and Gatewood, C.V: 1978, Astrophys. J., 225, 191.CrossRefGoogle Scholar
Hamada, T., and Saltpeter, E.E. : 1961, Astrophys. J., 134, 683.CrossRefGoogle Scholar
Holberg, J.B., Wesemael, F., and Hubeny, I.: 1984, Astrophys. J., 280, 679.CrossRefGoogle Scholar
Holberg, J.B., Wesemael, F., and Basile, J.: 1986, Astrophys. J., 306, 329.CrossRefGoogle Scholar
Mewe, R., Heise, J., Groneschild, E.H.B.M., Brinkman, A.C., Schrijver, J. and Den Boggende, A.J.F.: 1975, Nature Phys. Sci., 256, 711.CrossRefGoogle Scholar
Paerels, F.B.S., et al.: 1988, Astrophys. J., 329, 849.CrossRefGoogle Scholar
Shipman, H.L. : 1976, Astrophys. J. (Letters), 206, L67.CrossRefGoogle Scholar
Thejll, P., and Shipman, H.L. : 1987, Pub. Astron. Soc. Pacific, 98, 922.CrossRefGoogle Scholar