Comet 29P/Schwassmann-Wachmann 1: The Appulse of 2020 December 8 and Future Prospects for Stellar Occultations, 2021-2029
Abstract
The stellar occultation method is a particularly powerful tool for probing the nature of distant solar system objects. Here we report a single observation of a close appulse of comet 29P/Schwassmann-Wachmann 1 to a 14 mag star that showed no significant deviation in the recordedlight curve on a 2.25 s time resolution (corresponding to 27 km in projected distance of 29P/SW1).From that we conclude that no significant debris (with sufficient optical depth) existed within 500-1000 km of its nucleus for this specific observation. A new orbit solution has been derived from high-precision astrometry from images taken over a 12-yrs interval using 2.0 m aperture telescopes in Hawaii and Australia (currently 587 positions with a mean residual of ~0.10"). This orbit (togetherwith that using the JPL Horizons ephemeris) has been used to predict two sets of stellar occultations involving 29P/SW1 through to end-2029. Of the 20 most favourable events, 7 take place within the space of 40 days, and four of these shadow paths cross North America. This unprecedented finding warrants a coordinated observing campaign during the crucial period, from 2022 December 19 to 2023 January 28.
- Publication:
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Journal for Occultation Astronomy
- Pub Date:
- July 2021
- Bibcode:
- 2021JOA....11c...3M