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Refining our knowledge of the white dwarf mass-radius relation with HST observations of Sirius-type binaries

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journal contribution
posted on 24.02.2017, 14:53 by M. A. Barstow, H. E. Bond, M. R. Burleigh, S. L. Casewell, J. Farihi, J. B. Holberg, I. Hubeny
The presence of a white dwarf in a resolved binary system, such as Sirius, provides an opportunity to combine dynamical information about the masses, from astrometry and spectroscopy, with a gravitational red-shift measurement and spectrophotometry of the white dwarf atmosphere to provide a test of theoretical mass-radius relations of unprecedented accuracy. We demonstrated this with the first Balmer line spectrum of Sirius B to be obtained free of contamination from the primary, with STIS on HST. However, we also found an unexplained discrepancy between the spectroscopic and gravitational red-shift mass determinations. With the recovery of STIS, we have been able to revisit our observations of Sirius B with an improved observation strategy designed to reduce systematic errors on the gravitational red-shift measurement. We provide a preliminary report on the refined precision of the Sirius B mass-radius measurements and the extension of this technique to a larger sample of white dwarfs in resolved binaries. Together these data can provide accurate mass and radius determinations capable of testing the theoretical mass-radius relation and distinguishing between possible structural models.

Funding

MAB acknowledges support from the GAIA post-launch support programme of the UK Space Agency. SLC acknowledges support from the College of Science and Engineering at the University of Leicester.

History

Citation

ASP Conference Series, 2015, 493, p. 307

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy

Source

19th European Workshop on White Dwarfs, Proceedings of a conference held at the Université de Montréal, Montréal, Canada

Version

AM (Accepted Manuscript)

Published in

ASP Conference Series

Publisher

Astronomical Society of the Pacific

issn

1050-3390

Copyright date

2015

Available date

24/02/2017

Publisher version

http://adsabs.harvard.edu/abs/2015ASPC..493..307B

Temporal coverage: start date

11/08/2014

Temporal coverage: end date

15/08/2014

Language

en

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