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Open Astronomy

formerly Baltic Astronomy

Editor-in-Chief: Barbuy, Beatriz


IMPACT FACTOR 2018: 0.350

CiteScore 2018: 0.24

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ICV 2017: 121.03

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2543-6376
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Volume 27, Issue 1

Issues

New observations and asteroseismic analysis of the subdwarf B pulsator PG 1219+534

Valérie Van Grootel
  • Corresponding author
  • Space sciences, Technologies, and Astrophysics Research (STAR) Institute, Liège University, 19C Allée du six-aout, B-4000 Liège, Belgium
  • Email
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Marie-Julie Péters
  • Space sciences, Technologies, and Astrophysics Research (STAR) Institute, Liège University, 19C Allée du six-aout, B- 4000 Liège, Belgium
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Elizabeth M. Green
  • Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ, 85721, United States of America
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/ Stéphane Charpinet / Pierre Brassard
  • Département de Physique, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Gilles Fontaine
  • Département de Physique, Université de Montréal, CP 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2018-03-24 | DOI: https://doi.org/10.1515/astro-2018-0014

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 (Teff = 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), rather thin H-He envelope (log q(envl) = −3.75 ± 0.12), and close to He-burning exhaustion (Xcore(C + O) = 0.86 ± 0.05).We also investigate the internal rotation of the star.We find that PG 1219+534 rotates very slowly (Prot = 34.91 ± 0.84 days) and that solid-body rotation is reached at least down to ∼60% of the radius.

Keywords: subdwarfs; stars: oscillation; stars:interior; stars: individual: PG 1219+534

References

  • Blanchette, J.-P., Chayer, P., Wesemael, F., Fontaine, G., Fontaine, M., Dupuis, J. et al. 2008, ApJ, 678, 1329-1341.Google Scholar

  • Charpinet, S., Fontaine, G., Brassard, P., & Dorman, B. 1996, ApJ, 471, L103-106.Google Scholar

  • Charpinet, S., Fontaine, G., Brassard, P., Chayer, P., Rogers, F. J., Iglesias, C. A. et al. 1997, ApJ, 483, L123-L126.Google Scholar

  • Charpinet, S., Fontaine, G., Brassard, P., Green, E. M., & Chayer, P. 2005, A&A, 437, 575-597.Google Scholar

  • Charpinet, S., Van Grootel, V., Reese, D., Fontaine, G., Green, E. M., Brassard, P. et al. 2008, A&A, 489, 377-394.Google Scholar

  • Charpinet, S., Van Grootel, V., Fontaine, G., Green, E. M., Brassard, P., Randall, S. K. et al. 2011, A&A, 530, A3.Google Scholar

  • Dorman, B., Rood, R. T., & O’Connell, R. W. 1993, ApJ, 419, 596-614.Google Scholar

  • Fontaine, G., Brassard, P., Charpinet, S., Green, E. M., Chayer, P., Billéres, M. et al. 2003, ApJ, 597, 518-534.Google Scholar

  • Giammichele, N., Fontaine, G., Brassard, P., & Charpinet, S. 2016, ApJS, 223, 10.Google Scholar

  • Giammichele, N., Charpinet, S., Brassard, P. & Fontaine, G. 2017, A&A, 598, A109.Google Scholar

  • Han, Z., Podsiadlowski, P., Maxted, P. F. L., Marsh, T. R., & Ivanova, N. 2002, MNRAS, 336, 449-466.Google Scholar

  • Han, Z., Podsiadlowski, P., Maxted, P. F. L., & Marsh, T. R. 2003, MNRAS, 341, 669-691.Google Scholar

  • Koen, C., O’Donoghue, D., Pollacco, D. L., & Charpinet, S. 1999, MNRAS, 305, 28-38.Google Scholar

  • Randall, S. K., Fontaine, G., Brassard, P., & Bergeron, P. 2005, ApJS, 161, 456-479.PubMedGoogle Scholar

  • Tremblay, P.-E., Fontaine, G., Brassard, P., Bergeron, P., & Randall, S. K. 2006, ApJS, 165, 551-567.Google Scholar

  • Unno, W., Osaki, Y., Ando, H., & Shibahashi, H. 1979, Nonradial oscillations of stars, University of Tokyo Press, Japan.Google Scholar

  • Van Grootel, V., Charpinet, S., Fontaine, G., Brassard, P., Green, E. M., Chayer, P. et al. 2008, A&A, 488, 685-696.Google Scholar

  • Van Grootel, V., Charpinet, S., Brassard, P., Fontaine, G., & Green, E. M. 2013, A&A, 553, A97.Google Scholar

About the article

Received: 2017-09-30

Accepted: 2017-12-26

Published Online: 2018-03-24


Citation Information: Open Astronomy, Volume 27, Issue 1, Pages 44–56, ISSN (Online) 2543-6376, DOI: https://doi.org/10.1515/astro-2018-0014.

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© 2018, published by De Gruyter. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. BY-NC-ND 4.0

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