A Look at Outbursts of Comet C/2014 UN 271 (Bernardinelli–Bernstein) near 20 au

Kelley, Michael S. P. and Kokotanekova, Rosita and Holt, Carrie E. and Protopapa, Silvia and Bodewits, Dennis and Knight, Matthew M. and Lister, Tim and Usher, Helen and Chatelain, Joseph and Gomez, Edward and Greenstreet, Sarah and Angel, Tony and Wooding, Ben (2022) A Look at Outbursts of Comet C/2014 UN 271 (Bernardinelli–Bernstein) near 20 au. The Astrophysical Journal Letters, 933 (2). L44. ISSN 2041-8205

[thumbnail of Kelley_2022_ApJL_933_L44.pdf] Text
Kelley_2022_ApJL_933_L44.pdf

Download (3MB)

Abstract

Cometary activity may be driven by ices with very low sublimation temperatures, such as carbon monoxide ice, which can sublimate at distances well beyond 20 au. This point is emphasized by the discovery of the Oort cloud comet C/2014 UN271 (Bernardinelli–Bernstein) and its observed activity out to ∼26 au. Through observations of this comet's optical brightness and behavior, we can potentially discern the drivers of activity in the outer solar system. We present a study of the activity of comet Bernardinelli–Bernstein with broad-band optical photometry taken at 19–20 au from the Sun (2021 June to 2022 February) as part of the LCO Outbursting Objects Key (LOOK) Project. Our analysis shows that the comet's optical brightness during this period was initially dominated by cometary outbursts, stochastic events that ejected ∼107 to ∼108 kg of material on short (<1 day) timescales. We present evidence for three such outbursts occurring in 2021 June and September. The nominal nuclear volumes excavated by these events are similar to the 10–100 m pit-shaped voids on the surfaces of short-period comet nuclei, as imaged by spacecraft. Two out of three Oort cloud comets observed at large pre-perihelion distances exhibit outburst behavior near 20 au, suggesting such events may be common in this population. In addition, quiescent CO-driven activity may account for the brightness of the comet in 2022 January to February, but that variations in the cometary active area (i.e., the amount of sublimating ice) with heliocentric distance are also possible.

Item Type: Article
Subjects: East India library > Physics and Astronomy
Depositing User: Unnamed user with email support@eastindialibrary.com
Date Deposited: 26 Apr 2023 06:58
Last Modified: 24 May 2024 06:50
URI: http://info.paperdigitallibrary.com/id/eprint/906

Actions (login required)

View Item
View Item