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Multi-periodic pulsations of a stripped red-giant star in an eclipsing binary system

Maxted, Pierre F. L.; Serenelli, Aldo M.; Miglio, Andrea; Marsh, Thomas R.; Heber, Ulrich; Dhillon, Vikram S.; Littlefair, Stuart; Copperwheat, Chris; Smalley, Barry; Breedt, Elmé; Schaffenroth, Veronika

Authors

Aldo M. Serenelli

Andrea Miglio

Thomas R. Marsh

Ulrich Heber

Vikram S. Dhillon

Stuart Littlefair

Chris Copperwheat

Elmé Breedt

Veronika Schaffenroth



Abstract

Low-mass white-dwarf stars are the remnants of disrupted red-giant stars in binary millisecond pulsars1 and other exotic binary star systems2,3,4. Some low-mass white dwarfs cool rapidly, whereas others stay bright for millions of years because of stable fusion in thick surface hydrogen layers5. This dichotomy is not well understood, so the potential use of low-mass white dwarfs as independent clocks with which to test the spin-down ages of pulsars6,7 or as probes of the extreme environments in which low-mass white dwarfs form8,9,10 cannot fully be exploited. Here we report precise mass and radius measurements for the precursor to a low-mass white dwarf. We find that only models in which this disrupted red-giant star has a thick hydrogen envelope can match the strong constraints provided by our data. Very cool low-mass white dwarfs must therefore have lost their thick hydrogen envelopes by irradiation from pulsar companions11,12 or by episodes of unstable hydrogen fusion (shell flashes). We also find that this low-mass white-dwarf precursor is a type of pulsating star not hitherto seen. The observed pulsation frequencies are sensitive to internal processes that determine whether this star will undergo shell flashes.

Citation

Maxted, P. F. L., Serenelli, A. M., Miglio, A., Marsh, T. R., Heber, U., Dhillon, V. S., …Schaffenroth, V. (2013). Multi-periodic pulsations of a stripped red-giant star in an eclipsing binary system. Nature, 498(7455), 463-465. https://doi.org/10.1038/nature12192

Journal Article Type Article
Acceptance Date Apr 15, 2013
Online Publication Date Jun 26, 2013
Publication Date 2013-06
Deposit Date Jun 16, 2023
Journal Nature
Print ISSN 0028-0836
Electronic ISSN 1476-4687
Publisher Nature Publishing Group
Peer Reviewed Peer Reviewed
Volume 498
Issue 7455
Pages 463-465
DOI https://doi.org/10.1038/nature12192
Keywords Multidisciplinary