The most massive heartbeat: an in-depth analysis of ι Orionis
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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2017
- DOI:
- 10.1093/mnras/stx207
- arXiv:
- arXiv:1703.02086
- Bibcode:
- 2017MNRAS.467.2494P
- Keywords:
-
- binaries: close;
- stars: fundamental parameters;
- stars: individual: ι Ori;
- stars: massive;
- stars: oscillations;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 11 pages, 5 figures, 3 tables Monthly Notices of the Royal Astronomical Society, in press