Recent Cryovolcanic Activity of Comet 29P/Schwassmann-Wachmann 1
Abstract
The centaur Comet 29P/SW1 is a large 60-km object which appears to be uniquely active, almost certainly as a consequence of an extremely slow (57-d) rotation rate of its nucleus. It exhibits outbursts, which are explosive by nature and some of which appear to be associated with enduring cryovolcanoes. High-cadence precision photometry during 2014-2016 has quantified its recent behaviour in unprecedented detail. Photometry of the inner coma showing more than 20 discrete outbursts will be presented and discussed in relation to a gas-exsolution mechanism involving sub-crustal liquid phases. The results to be shown confirm earlier findings that a single outburst can trigger one or more follow-up outbursts from other sources within a few days of the initial event. Given that this object is most probably a recent interloper into the inner solar system, having originated from the trans-Neptunian region, it is a worthy target for further investigation. Its large nucleus and Hill sphere radius of ~30000 km would facilitate an orbiting probe, and with an escape velocity of ~20 m/s, its inner coma would be expected to clear relatively rapidly during quiescent intervals that can last for several months. Given its likely provenance as a TNO, prompt ground-based spectroscopic observation of its expanding coma following bright outbursts, which appear to arise from various locations on its nucleus, is to be encouraged.
- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #48
- Pub Date:
- October 2016
- Bibcode:
- 2016DPS....4820604M