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WR20a: a massive cornerstone binary system comprising two extreme early-type stars

G. Rauw·M. De Becker·Y. Naze·P. A. Crowther·E. Gosset·H. Sana·K. A. van der Hucht·J. -M. Vreux·P. M. Williams
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Abstract

We analyse spectroscopic observations of WR20a revealing that this star is a massive early-type binary system with a most probable orbital period of \sim 3.675 days. Our spectra indicate that both components are most likely of WN6ha or O3If^*/WN6ha spectral type. The orbital solution for a period of 3.675 days yields extremely large minimum masses of 70.7 \pm 4.0 and 68.8 \pm 3.8 M_{\odot} for the two stars. These properties make WR20a a cornerstone system for the study of massive star evolution.

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G. Rauw, M. De Becker, Y. Naze, P. A. Crowther, E. Gosset, H. Sana, K. A. van der Hucht, J. -M. Vreux, P. M. Williams. 2004-04-28. WR20a: a massive cornerstone binary system comprising two extreme early-type stars. https://doi.org/10.1051/0004-6361%3A20040150

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