Apparent Outburst of Comet 29P/Schwassmann-Wachmann
ATel #14898; Kritti Sharma (IITB), Michael S. P. Kelley (U. Maryland), Vishwajeet Swain (IITB), Harsh Kumar (IITB), Urgain Stanzin (IAO), Varun Bhalerao (IITB), G. C. Anupama (IIA), Sudhanshu Barway (IIA) on behalf of the GROWTH India Collaboration and Zwicky Transient Facility Collaboration
on 6 Sep 2021; 16:34 UT
Distributed as an Instant Email Notice Comets
Credential Certification: Varun Bhalerao (varunb@iitb.ac.in)
We report the discovery of an outburst of comet 29P/Schwassmann-Wachmann in GROWTH India Telescope (GIT) data. On 2021 September 4.804 UTC, the comet had an apparent brightness of r = 16.00 +/- 0.03 mag. In our second epoch on 2021 September 4.904 UTC, the comet had brightened to r = 15.17 +/- 0.03 mag. By our third epoch on 2021 September 4.953 UTC, the comet's magnitude was sustained at r = 15.05 +/- 0.04 mag, thereby suggesting an outburst strength of -0.95 +/- 0.05 mag. The averaged photometry for each epoch is measured with a 5" radius aperture. The magnitudes are calibrated against PanSTARRS PS1 data release (Flewelling et al., 2018). During our observations, the comet was at 5.910 AU from the Sun and 5.881 AU from the Earth. The event was confirmed in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP, 131, a8002) data, where the comet had brightened from g = 16.03 +/- 0.04 mag on 2021 September 2.456 UTC to r = 15.05 +/- 0.02 mag on 2021 September 5.425 UTC. The g-r colour of the comet is 0.53 mag, as measured from GIT and ZTF data.
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/
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 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.
