The most massive heartbeat

Author(s)
Herbert Pablo, Noel D. Richardson, J. Fuller, Rainer Kuschnig, Werner Wolfgang Weiss, J. Rowe, Anthony F J Moffat, A. Popowicz, Gerald Handler, Coralie Neiner, Andrzej Pigulski, Gregg A. Wade, B. Buysschaert, Tahina Ramiaramanantsoa, A. D. Bratcher, C. J. Gerhartz, J. J. Greco, K. Hardegree-Ullman, L. Lembryk, W. L. Oswald
Abstract

ι Ori is a well-studied massive binary consisting of an O9 III + B1 III/IV star. Due to its high eccentricity (e = 0.764) and short orbital period (Porb = 29.133 76 d), it has been considered to be a good candidate to show evidence of tidal effects; however, none have previously been identified. Using photometry from the BRIght Target Explorer (BRITE)-Constellation space photometry mission, we have confirmed the existence of tidal distortions through the presence of a heartbeat signal at periastron. We combine spectroscopic and light-curve analyses to measure the masses and radii of the components, revealing ι Ori to be the most massive heartbeat system known to date. In addition, using a thorough frequency analysis, we also report the unprecedented discovery of multiple tidally induced oscillations in an O star. The amplitudes of the pulsations allow us to empirically estimate the tidal circularization rate, yielding an effective tidal quality factor Q ~ 4 × 104.

Organisation(s)
Department of Astrophysics
External organisation(s)
California Institute of Technology (Caltech), University of Montreal, Technische Universität Graz, University of Toledo, Silesian University of Technology, Polish Academy of Sciences (PAS), Université de recherche Paris Sciences et Lettres, University of Wrocław, Royal Military College of Canada
Journal
Monthly Notices of the Royal Astronomical Society
Volume
467
Pages
2494-2503
No. of pages
10
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stx207
Publication date
05-2017
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/4ac49af1-2dbb-408c-8f29-51c8ad4c12a9