Romero, A.D., Lauffer, G.R., Istrate, A.G. et al. (1 more author) (2022) Uncovering the chemical structure of the pulsating low-mass white dwarf SDSS J115219.99+024814.4. Monthly Notices of the Royal Astronomical Society, 510 (1). pp. 858-869. ISSN 0035-8711
Abstract
Pulsating low-mass white dwarf stars are white dwarfs with stellar masses between 0.30 M⊙ and 0.45 M⊙ that show photometric variability due to gravity-mode pulsations. Within this mass range, they can harbour both a helium- and hybrid-core, depending if the progenitor experienced helium-core burning during the pre-white dwarf evolution. SDSS J115219.99+024814.4 is an eclipsing binary system where both components are low-mass white dwarfs, with stellar masses of 0.362±0.014 M⊙ and 0.325±0.013 M⊙. In particular, the less massive component is a pulsating star, showing at least three pulsation periods of ∼1314 s, ∼1069 s and ∼582.9 s. This opens the way to use asteroseismology as a tool to uncover its inner chemical structure, in combination with the information obtained using the light-curve modelling of the eclipses. To this end, using binary evolutionary models leading to helium- and hybrid-core white dwarfs, we compute adiabatic pulsations for ℓ = 1 and ℓ = 2 gravity modes with Gyre. We found that the pulsating component of the SDSS J115219.99+024814.4 system must have a hydrogen envelope thinner that the value obtained from binary evolution computations, independently of the inner composition. Finally, from our asteroseismological study, we find a best fit model characterised by Teff = 10 917 K, M=0.338 M⊙, MH = 10−6 M⊙ with the inner composition of a hybrid WD.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 The Author(s). This is an author-produced version of a paper subsequently published in Monthly Notices of the Royal Astronomical Society. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | asteroseismology; white dwarfs; binaries |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number Science and Technology Facilities Council ST/R003424/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 13 Dec 2021 13:43 |
Last Modified: | 16 Mar 2022 11:40 |
Status: | Published |
Publisher: | Oxford University Press (OUP) |
Refereed: | Yes |
Identification Number: | 10.1093/mnras/stab3487 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:181517 |