Massive Binary WR 112 and Properties of Wolf-Rayet Dust
Abstract
Some hot, massive, Population I Wolf-Rayet (W-R) 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, multiarc dust envelope around the star WR 112, 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 μm, significantly larger than theoretical limits. The dust production rate is 6.1×10-7 Msolar yr-1, and the total detectable dust mass is found to be about 2.8×10-5 Msolar (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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2002
- DOI:
- 10.1086/339138
- arXiv:
- arXiv:astro-ph/0112403
- Bibcode:
- 2002ApJ...565L..59M
- Keywords:
-
- Infrared: Stars;
- Stars: Winds;
- Outflows;
- Stars: Wolf-Rayet;
- Astrophysics
- E-Print:
- 8pp, 3 figures (2 of them in colour). The Astrophysical Journal Letters (2002) in press