Pan-STARRS 1 Observations of the Unusual Active Centaur P/2011 S1(Gibbs)

Lin, H.W.; Chen, Y.T.; Lacerda, P.; Ip, W.H.; Holman, M.; Protopapas, P.; Chen, W.P.; Burgett, W.S.; Chambers, K.C.; Flewelling, H.; Huber, M.E.; Jedicke, R.; Kaiser, N.; Magnier, E.A.; Metcalfe, N.; Price, P.A.

Abstract

P/2011 S1 (Gibbs) is an outer solar system comet or active Centaur with a similar orbit to that of the famous 29P/Schwassmann-Wachmann 1. P/2011 S1 (Gibbs) has been observed by the Pan-STARRS 1 (PS1) sky survey from 2010 to 2012. The resulting data allow us to perform multi-color studies of the nucleus and coma of the comet. Analysis of PS1 images reveals that P/2011 S1 (Gibbs) has a small nucleus <4 km radius, with colors g P1 – r P1 = 0.5 ± 0.02, r P1 – i P1 = 0.12 ± 0.02, and i P1 – z P1 = 0.46 ± 0.03. The comet remained active from 2010 to 2012, with a model-dependent mass-loss rate of ~100 kg s–1. The mass-loss rate per unit surface area of P/2011 S1 (Gibbs) is as high as that of 29P/Schwassmann-Wachmann 1, making it one of the most active Centaurs. The mass-loss rate also varies with time from ~40 kg s–1 to 150 kg s–1. Due to its rather circular orbit, we propose that P/2011 S1 (Gibbs) has 29P/Schwassmann-Wachmann 1-like outbursts that control the outgassing rate. The results indicate that it may have a similar surface composition to that of 29P/Schwassmann-Wachmann 1. Our numerical simulations show that the future orbital evolution of P/2011 S1 (Gibbs) is more similar to that of the main population of Centaurs than to that of 29P/Schwassmann-Wachmann 1. The results also demonstrate that P/2011 S1 (Gibbs) is dynamically unstable and can only remain near its current orbit for roughly a thousand years.

Citation

Lin, H., Chen, Y., Lacerda, P., Ip, W., Holman, M., Protopapas, P., …Price, P. (2014). Pan-STARRS 1 Observations of the Unusual Active Centaur P/2011 S1(Gibbs). Astronomical Journal, 147(5), Article 114. https://doi.org/10.1088/0004-6256/147/5/114

• Journal Article Type: Article
• Acceptance Date: Feb 24, 2014
• Publication Date: May 1, 2014
• Deposit Date: Jun 16, 2015
• Publicly Available Date: Jun 30, 2015
• Journal: Astronomical Journal
• Print ISSN: 0004-6256
• Electronic ISSN: 1538-3881
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 147
• Issue: 5
• Article Number: 114
• DOI: https://doi.org/10.1088/0004-6256/147/5/114
• Keywords: Comets: general, Kuiper belt objects: individual (Centaur asteroid).
• Public URL: https://durham-repository.worktribe.com/output/1436236