New observations and asteroseismic analysis of the subdwarf B pulsator PG 1219+534
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Author
Van Grootel, ValériePéters, Marie-Julie
Green, Elizabeth M.
Charpinet, Stéphane
Brassard, Pierre
Fontaine, Gilles
Affiliation
Univ Arizona, Steward ObservIssue Date
2018-02
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DE GRUYTER POLAND SP ZOOCitation
Open Astronomy, Volume 27, Issue 1, Pages 44–56, ISSN (Online) 2543-6376, DOI: https://doi.org/10.1515/astro-2018-0014.Journal
OPEN ASTRONOMYRights
© 2018, published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
We present a new asteroseismic modeling of the hot B subdwarf (sdB) pulsator PG 1219+534, based on a 3-month campaign with the Mont4K/Kuiper combination at Mt Bigelow (Arizona) and on updated atmospheric parameters from high S/N low and medium resolution spectroscopy. On the basis of the nine independent pulsation periods extracted from the photometric light curve, we carried out an astroseismic analysis by applying the forward modeling approach using our latest (third and fourth generation) sdB models. Atmospheric parameters (T-eff = 34 258 +/- 170 K, log g = 5.838 +/- 0.030) were used as independent constraints, as well as partial mode identification based on observed multiplet structures we ascribed to stellar rotation. The optimal model found is remarkably consistent between various analyses with third and fourth generation of sdB models, and also with previously published analysis with second generation sdB models. It corresponds to a sdB with a canonical mass (0.46 +/- 0.02 M-circle dot), rather thin H-He envelope (log q(envl) = -3.75 +/- 0.12), and close to He-burning exhaustion (X-core(C + O) = 0.86 +/- 0.05). We also investigate the internal rotation of the star. We find that PG 1219+534 rotates very slowly (P-rot = 34.91 +/- 0.84 days) and that solid-body rotation is reached at least down to similar to 60% of the radius.Note
Open access journal.ISSN
2543-6376Version
Final published versionAdditional Links
http://www.degruyter.com/view/j/astro.2018.27.issue-1/astro-2018-0014/astro-2018-0014.xmlae974a485f413a2113503eed53cd6c53
10.1515/astro-2018-0014