Apparent Outburst of Comet 67P/Churyumov-Gerasimenko
ATel #15053; Michael S. P. Kelley (U. Maryland), Kritti Sharma (IITB), Vishwajeet Swain (IITB), Harsh Kumar (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Sudhanshu Barway (IIA), Daniel Gardener (U. Edinburgh), Tim Lister (Las Cumbres Observatory), Helen Usher (Open University), Tony Angel (Harlingten Observatory) on behalf of the Zwicky Transient Facility Collaboration, GROWTH India Collaboration and the LCO Outbursting Objects Key Project
on 19 Nov 2021; 21:46 UT
Credential Certification: Tim Lister (tlister@lco.global)
We report an apparent outburst of comet 67P/Churyumov-Gerasimenko, discovered in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP, 131, a8002) and GROWTH-India Telescope (GIT) data. Photometry of the comet in the r-band (5" radius aperture, PS1 photometric system) was 12.06+/-0.02 and 12.16+/-0.02 mag on 2021 Nov 14 at 10:57 and Nov 16 at 20:23 UTC, respectively. The comet brightened to r=11.52+/-0.08 mag by the next observation on Nov 17 at 20:44 UTC, resulting in an apparent outburst strength of -0.64+/-0.08 mag in our photometric aperture. The event is confirmed in subsequent ZTF photometry, r= 11.66+/-0.03 and 11.70+/-0.03 on Nov 18 at 09:25 and 11:38 UTC, respectively and from the Las Cumbres Observatory (LCO) 2m Faulkes Telescope North (FTN)+MuSCAT3 four channel imager on Nov 18 11:20 UTC. The FTN photometry measured through the same 5â radius aperture is g=12.33+/-0.02, r=11.67+/-0.02, i=11.47+/-0.02 and z=11.39+/-0.04 mag. At the time of the outburst discovery with ZTF, the comet was 1.23 au from the Sun and 0.42 au from the Earth. The cometâs last perihelion passage was on 2021 Nov 2.
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.
This work makes use of observations from the Las Cumbres Observatory global telescope network. Based on observations made with the MuSCAT3 instrument, developed by the Astrobiology Center and under financial supports by JSPS KAKENHI (JP18H05439) and JST PRESTO (JPMJPR1775), at Faulkes Telescope North on Maui, HI, operated by the Las Cumbres Observatory. The FTN observations were obtained as part of the Comet Chasers school outreach program, by Tony Angel. The Comet Chasers program is part of the Faulkes Telescope Project (FTPEPO2014A-004), which is partly funded by the Dill Faulkes Educational Trust.
The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/
