• DOI:10.3847/PSJ/abfe11
• Corpus ID: 234470136

Six Outbursts of Comet 46P/Wirtanen

@article{Kelley2021SixOO,
  title={Six Outbursts of Comet 46P/Wirtanen},
  author={Michael S. P. Kelley and Tony L. Farnham and Jian-Yang Li and Dennis Bodewits and Colin Snodgrass and Johannes Allen and Eric C. Bellm and Michael W. Coughlin and Andrew J. Drake and D. Duev and Matthew J. Graham and Thomas Kupfer and Frank J. Masci and Daniel J. Reiley and R. Walters and Martin Dominik and U. G. J{\o}rgensen and Adam Andrews and Nanna Bach-M{\o}ller and Valerio Bozza and Martin J. Burgdorf and Justyn Campbell-White and Sami Dib and Yuri I. Fujii and Tobias C. Hinse and M. Hundertmark and E. Khalouei and Pen{\'e}lope Longa-Pe{\~n}a and Markus Rabus and Sohrab Rahvar and Sedighe Sajadian and Jesper F. Skottfelt and John Southworth and J Tregloan-Reed and Eduardo Unda-Sanzana},
  journal={The Planetary Science Journal},
  year={2021},
  volume={2}
}

• M. Kelley, T. Farnham, +32 authors E. Unda-Sanzana
• Published 12 May 2021
• Physics, Geology
• The Planetary Science Journal

Cometary activity is a manifestation of sublimation-driven processes at the surface of nuclei. However, cometary outbursts may arise from other processes that are not necessarily driven by volatiles. In order to fully understand nuclear surfaces and their evolution, we must identify the causes of cometary outbursts. In that context, we present a study of mini-outbursts of comet 46P/Wirtanen. Six events are found in our long-term lightcurve of the comet around its perihelion passage in 2018. The apparent strengths range from −0.2 to −1.6 mag in a 5″ radius aperture and correspond to dust masses between ∼104 and 106 kg, but with large uncertainties due to the unknown grain size distributions. However, the nominal mass estimates are on the same order of magnitude as the mini-outbursts at comet 9P/Tempel 1 and 67P/Churyumov-Gerasimenko, events that were notably lacking at comet 103P/Hartley 2. We compare the frequency of outbursts at the four comets, and suggest that the surface of 46P has large-scale (∼10–100 m) roughness that is intermediate to that of 67P and 103P, if not similar to the latter. The strength of the outbursts appear to be correlated with time since the last event, but a physical interpretation with respect to solar insolation is lacking. We also examine Hubble Space Telescope images taken about two days following a near-perihelion outburst. No evidence for macroscopic ejecta was found in the image, with a limiting radius of about 2 m.