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Massive Binary WR112 and Properties of Wolf-Rayet Dust

S. V. Marchenko·A. F. J. Moffat·W. D. Vacca·S. Cote·R. Doyon
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Abstract

Some hot, massive, population-I Wolf-Rayet (WR) stars of the carbon subclass are known to be prolific dust-producers. How dust can form in such a hostile environment remains a mystery. Here we report the discovery of a relatively cool, extended, multi-arc dust envelope around the star WR112, most likely formed by wind-wind collision in a long-period binary system. We derive the binary orbital parameters, the dust temperature and the dust mass distributions in the envelope. We find that amorphous carbon is a main constituent of the dust, in agreement with earlier estimates and theoretical predictions. However, the characteristic size of the dust grains is estimated to be ~1 micron, significantly larger than theoretical limits. The dust production rate is 6.1*10^[-7] M_Sun / yr and the total detectable dust mass is found to be about 2.8*10^[-5] M_Sun (for d=4.15 kpc). We also show that, despite the hostile environment, at least ~20% of the initially-formed dust may reach the interstellar medium.

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S. V. Marchenko, A. F. J. Moffat, W. D. Vacca, S. Cote, R. Doyon. 2001-12-17. Massive Binary WR112 and Properties of Wolf-Rayet Dust. https://doi.org/10.1086/339138

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