EPIC 216747137: A new HW Vir eclipsing binary with a massive sdOB primary and a low-mass M-dwarf companion
Silvotti R, Schaffenroth , Heber U, Ostensen RH, Telting JH, Vos J, Kilkenny D, Mancini L, Ciceri S, Irrgang A, Drechsel H (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 500
Pages Range: 2461-2474
Journal Issue: 2
Abstract
EPIC 216747137 is a new HW Virginis system discovered by the Kepler spacecraft during its K2 'second life'. Like the other HW Vir systems, EPIC 216747137 is a post-common-envelope eclipsing binary consisting of a hot subluminous star and a cool low-mass companion. The short orbital period of 3.87 h produces a strong reflection effect from the secondary (∼9 per cent in the R band). Together with AA Dor and V1828 Aql, EPIC 216747137 belongs to a small subgroup of HW Vir systems with a hot evolved sdOB primary. We find the following atmospheric parameters for the hot component: Teff = 40400 ± 1000 K, log g = 5.56 ± 0.06, and log(N(He)/N(H)) =-2.59 ± 0.05. The sdOB rotational velocity v sin i = 51 ± 10 km s-1 implies that the stellar rotation is slower than the orbital revolution and the system is not synchronized. When we combine photometric and spectroscopic results with the Gaia parallax, the best solution for the system corresponds to a primary with a mass of about 0.62 M close to, and likely beyond, the central helium exhaustion, while the cool M-dwarf companion has a mass of about 0.11 M.
Authors with CRIS profile
Ulrich Heber
Naturwissenschaftliche Fakultät
Andreas Irrgang
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut
Horst Drechsel
Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut
Involved external institutions
National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF)
Italy (IT)
Universität Potsdam
Germany (DE)
Missouri State University
United States (USA) (US)
Roque de los Muchachos Observatory / Observatorio del Roque de los Muchachos (ORM)
Spain (ES)
University of the Western Cape (UWC)
South Africa (ZA)
Stockholm University / Stockholms universitet
Sweden (SE)
Italy (IT)
Universität Potsdam
Germany (DE)
Missouri State University
United States (USA) (US)
Roque de los Muchachos Observatory / Observatorio del Roque de los Muchachos (ORM)
Spain (ES)
University of the Western Cape (UWC)
South Africa (ZA)
Stockholm University / Stockholms universitet
Sweden (SE)
How to cite
APA:
Silvotti, R., Schaffenroth, ., Heber, U., Ostensen, R.H., Telting, J.H., Vos, J.,... Drechsel, H. (2021). EPIC 216747137: A new HW Vir eclipsing binary with a massive sdOB primary and a low-mass M-dwarf companion. Monthly Notices of the Royal Astronomical Society, 500(2), 2461-2474. https://dx.doi.org/10.1093/mnras/staa3332
MLA:
Silvotti, R., et al. "EPIC 216747137: A new HW Vir eclipsing binary with a massive sdOB primary and a low-mass M-dwarf companion." Monthly Notices of the Royal Astronomical Society 500.2 (2021): 2461-2474.
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