Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-25T15:36:16.277Z Has data issue: false hasContentIssue false

Masses of DB Degenerate Dwarfs

Published online by Cambridge University Press:  12 April 2016

Virginia Trimble*
Affiliation:
Astronomy Program, U. Maryland, College Park MD 20742 USA and Dept. of Physics, U. California, Irvine CA 92717 USA

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.

Alcock (1979a,b) has suggested that DB degenerate dwarfs can only be kept observably free of accreted interstellar hydrogen if their masses are not more than about 0.3 M. This is distressing because (a) photometrically determined DB radii (hence masses) are not statistically different from those of DA’s (Shipman 1979), and (b) no one quite knows how to make a degenerate dwarf with this low a mass in the age of the galaxy. Several authors (Vauclair et al. 1979; Michaud and Fontaine 1979) have suggested that accretion is inhibited by effects of coronae and/or magnetic fields. I address here the possibility that the DB’s are a somewhat higher velocity population than the general run of degenerate dwarfs. Although, as we shall see, this may imply somewhat lower than average masses for them, the dominant effect will be reduced accretion due to the high speed of the stars through the interstellar gas.

Type
Colloquium Session I
Copyright
Copyright © The University of Rochester 1979

References

Alcock, C. 1979a, Talk at California Institute of Technology Google Scholar
Alcock, C. 1979b, Elsewhere in this volume.Google Scholar
Greenstein, J.L. and Trimble, V. 1967. Astrophys. J. 149, 283.CrossRefGoogle Scholar
Michaud, G. and Fontaine, G. 1979. Astrophys. J. 229, 694.CrossRefGoogle Scholar
Paczyński, B. 1970. Acta Astron. 20, 47.Google Scholar
Shipman, H. 1979. Astrophys. J. 228, 240.Google Scholar
Tinsley, B.M. and Larson, R. 1978. Astrophys. J. 221, 554.Google Scholar
Trimble, V. and Greenstein, J.L. 1972. Astrophys. J. 177, 441.CrossRefGoogle Scholar
Vauclair, G., Vauclair, S., and Greenstein, J.L. 1979. Preprint.Google Scholar
Wegner, G. 1974. Mon. Not. Roy. Astron. Soc. 166, 271.Google Scholar