Apparent Outburst of Comet 22P/Kopff
ATel #14565; Michael S. P. Kelley (U. Maryland), Tim Lister (Las Cumbres Observatory), Kritti Sharma (IITB), Harsh Kumar (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Sudhanshu Barway (IIA) on behalf of the Zwicky Transient Facility Collaboration, LCO Outbursting Objects Key Project, and GROWTH India Collaboration
on 20 Apr 2021; 21:14 UT
Credential Certification: Tim Lister (tlister@lco.global)
We report on an apparent outburst of comet 22P/Kopff, initially found in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP, 131, a8002) data. The comet brightened from i=18.79+/-0.15 mag to r=17.93+/-0.05 mag between 2021 Apr 18.213 and 19.212 UTC, respectively. All photometry is measured in 5" radius apertures and in the PS1 magnitude system. We estimate coma colors based on observations taken during the prior 48 days (g-r=0.52+/-0.04 mag, r-i=0.26+/-0.06 mag), suggesting an outburst strength of -1.12+/-0.17 mag. The event is confirmed with GROWTH India Telescope and Las Cumbres Observatory data from a 1m telescope at the Siding Spring Observatory node, observed in the SDSS r' filter. Photometry since 2021 Apr 01 is tabulated below with heliocentric distance (rh), observer-comet distance (delta), effective r-band magnitude (r), and epoch-to-epoch variation in r (dr).
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, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the 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.
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 and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).
Date Tel rh delta Filt m m unc r dr
UTC au au mag mag mag mag
-------------- --- ----- ----- ---- ----- ----- ----- -----
2021-04-02.232 ZTF 3.289 2.453 r 18.97 0.07 18.97
2021-04-02.370 ZTF 3.288 2.454 g 19.39 0.19 18.87 -0.10
2021-04-03.199 ZTF 3.283 2.457 i 18.84 0.13 19.11 0.24
2021-04-04.270 ZTF 3.278 2.461 g 19.54 0.11 19.02 -0.09
2021-04-06.233 ZTF 3.267 2.470 g 19.28 0.09 18.76 -0.26
2021-04-06.289 ZTF 3.267 2.471 i 18.82 0.12 19.09 0.33
2021-04-08.233 ZTF 3.257 2.480 g 19.48 0.11 18.96 -0.13
2021-04-08.271 ZTF 3.256 2.480 r 19.05 0.08 19.05 0.09
2021-04-10.233 ZTF 3.246 2.491 g 19.53 0.11 19.01 -0.04
2021-04-10.271 ZTF 3.246 2.491 r 18.82 0.07 18.82 -0.19
2021-04-12.249 ZTF 3.235 2.502 i 18.69 0.11 18.96 0.14
2021-04-12.292 ZTF 3.235 2.502 r 18.97 0.07 18.97 0.01
2021-04-15.212 ZTF 3.219 2.520 r 18.94 0.07 18.94 -0.03
2021-04-17.214 ZTF 3.208 2.533 r 18.96 0.08 18.96 0.02
2021-04-18.213 ZTF 3.203 2.539 i 18.79 0.15 19.05 0.09
2021-04-19.212 ZTF 3.197 2.546 r 17.93 0.05 17.93 -1.12
2021-04-19.761 GIT 3.194 2.550 r 18.16 0.03 18.16 0.23
2021-04-20.383 LCO 3.191 2.554 r 18.09 0.03 18.09 -0.07