Extensive study of HD 25558, a long-period double-lined binary with two SPB components
- Author(s)
- , A Sodor, Peter De Cat, D. J. Wright, Thomas Kallinger, Coralie Neiner, Maryline Briquet, P Lampens, R. J. Dukes, G.W. Henry, M. H. Williamson, E. Brunsden, Karen R. Pollard, Peter L. Cottrell, F. Maisonneuve, Pamela M. Kilmartin, J. Matthews, P. G. Beck, E Kambe, C. A. Engelbrecht, R. J. Czanik, S. Yang, O Hashimoto, S. Honda, Jian Ning Fu, B. Castanheira, Holger Lehmann, Zs Bognár, N. Behara, S. Scaringi, H Van Winckel, J. Menu, A. Lobel, P. Mathias, Sophie Saesen, M Vuckovic
- Abstract
We carried out an extensive observational study of the Slowly Pulsating B (SPB) star, HD 25558. The ≈2000 spectra obtained at different observatories, the ground-based and MOST satellite light curves revealed that this object is a double-lined spectroscopic binary with an orbital period of about nine years. The observations do not allow the inference of an orbital solution. We determined the physical parameters of the components, and found that both lie within the SPB instability strip. Accordingly, both show line-profile variations due to stellar pulsations. 11 independent frequencies were identified in the data. All the frequencies were attributed to one of the two components based on pixel-by-pixel variability analysis of the line profiles. Spectroscopic and photometric mode identification was also performed for the frequencies of both stars. These results suggest that the inclination and rotation of the two components are rather different. The primary is a slow rotator with ≈6 d period, seen at ≈60° inclination, while the secondary rotates fast with ≈1.2 d period, and is seen at ≈20° inclination. Spectropolarimetric measurements revealed that the secondary component has a magnetic field with at least a few hundred Gauss strength, while no magnetic field can be detected in the primary.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Hungarian Academy of Sciences, Royal Observatory of Belgium, University of New South Wales, College of Charleston, Tennessee State University, University of Canterbury, University of British Columbia (UBC), University of Johannesburg (UJ), North-West University, Gunma Astronomical Observatory, University of Hyogo, University of Texas, Austin, Université Libre de Bruxelles, University of Toulouse, Centre National de la Recherche Scientifique (CNRS), Strasbourg , Université Paris VII - Paris-Diderot, Université de Liège, National Astronomical Observatory of Japan, University of Victoria, Université de Genève, European Southern Observatory (Chile), Astronomical Observatory of Belgrade (AOB), Katholieke Universiteit Leuven, Beijing Normal University, Thüringer Landessternwarte Tautenburg
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 438
- Pages
- 3535-3556
- No. of pages
- 22
- ISSN
- 0035-8711
- DOI
- https://doi.org/10.1093/mnras/stt2466
- Publication date
- 03-2014
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/3ff22e61-36c0-479f-8df8-94357ed55439