Small Apparent Outburst of Comet 120P/Mueller 1
ATel #14876; Michael S. P. Kelley (U. Maryland) on behalf of the Zwicky Transient Facility Collaboration
on 26 Aug 2021; 21:37 UT
Credential Certification: Bryce Bolin (bolin.astro@gmail.com)
We report an apparent outburst of comet 120P/Mueller 1 discovered in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP, 131, a8002) photometry, measured in 7" radius apertures and calibrated to the PS1 photometric system. On 2021 Aug 01 at 11:33 UTC, the comet had an apparent r-band magnitude of 20.5+/-0.3 mag. The comet brightened to r=19.08+/-0.08 mag by the next set of data taken Aug 08 at 11:38 UTC. The outburst was subsequently confirmed on Aug 09 at 11:38 UTC, when the comet had a brightness of r=19.14+/-0.10 mag. The 7" radius aperture encompasses the full extent of the ejecta in the first post-outburst image. Altogether, the apparent outburst had a strength of -1.4+/-0.3 mag. The comet was at 2.55 au from the Sun and 3.00 au from the Earth.
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.
