Possible Disruption of C/2020 J1 (SONEAR)
ATel #15767; Quanzhi Ye (University of Maryland), Michael S. P. Kelley (University of Maryland), on behalf of the Zwicky Transient Facility Collaboration
on 19 Nov 2022; 00:19 UT
Credential Certification: Kumar Venkataramani (kumarv@caltech.edu)
We report the possible disruption of comet C/2020 J1 (SONEAR), identified in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP 131, a8002) data. Photometry of the comet measured using a 5-arcsec radius aperture shows a slight brightening in absolute magnitude after perihelion on 2021 April 18, followed by a rapid fading following r_h^-5 to ^-6 (where r_h is the heliocentric distance of the comet). The exact start date of the fading is unclear due to a gap in the monitoring owing to the comet going into solar conjunction, but should be between July and November of 2021. As of late October 2022, the comet appeared very diffuse, with a coma measured about 15-arcsec in diameter without a clear nucleus. Selected r-band photometry in the PS1 magnitude system, dates in UTC, and apertures centroided on the ephemeris position: 2021 May 15.31, 14.19 (0.03); 2021 Jul 12.19, 14.80 (0.02); 2021 Dec 02.56, 15.55 (0.02); 2022 Mar 03.41, 16.19 (0.02); 2022 May 08.24, 16.96 (0.03); 2022 Aug 06.16, 17.85 (0.06); 2022 Oct 30.53, 18.46 (0.06).
Observations with the 4.3-m Lowell Discovery Telescope (LDT) on 2022 October 27 confirmed the behavior of the comet. In addition to the same diffuse coma observed by ZTF, LDT images showed a pseudo nucleus at r~21-21.5 mag, located approximately 4-arcsec southwest of the center of the coma. The light-curve and the morphology of the comet are indicative of a large-scale disruption event that occurred several months ago. The connection between the disruption event and the fading is unclear.
Based on observations obtained with the Samuel Oschin Telescope 48-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, Weizmann Institute for Science, Oskar Klein Center at Stockholm University, University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, TANGO Consortium of Taiwan, University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France. Operations are conducted by COO, IPAC, and UW.
These results made use of the Lowell Discovery Telescope (LDT) at Lowell Observatory. Lowell is a private, non-profit institution dedicated to astrophysical research and public appreciation of astronomy and operates the LDT in partnership with Boston University, the University of Maryland, the University of Toledo, Northern Arizona University and Yale University. The University of Maryland observing team consisted of Quanzhi Ye, James Bauer, Michaela Blain, Adeline Gicquel-Brodtke, Tony Farnham, Lori Feaga, Carrie Holt, Michael S. P. Kelley, Juan Luis Rizos, and Jessica Sunshine.
