The most massive heartbeat: an in-depth analysis of Ɩ Orionis.

Autor: Pablo, Herbert, Richardson, N. D., Fuller, J., Rowe, J., Moffat, A. F. J., Kuschnig, R., Popowicz, A., Handler, G., Neiner, C., Pigulski, A., Wade, G. A., Weiss, W., Buysschaert, B., Ramiaramanantsoa, T., Bratcher, A. D., Gerhartz, C. J., Greco, J. J., Hardegree-Ullman, K., Lembryk, L., Oswald, W. L.
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Zdroj: Monthly Notices of the Royal Astronomical Society; May2017, Vol. 467 Issue 2, p2494-2503, 10p
Abstrakt: Ɩ Ori is a well-studied massive binary consisting of an O9 ш + B1 ш/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 i 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. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index