M. S. P. Kelley and D. Bodewits, University of Maryland; and Q.-Z. Ye, Infrared Processing and Analysis Center, California Institute of Technology, on behalf of the Zwicky Transient Facility (ZTF) Solar System Working Group, report an outburst of comet 64P/Swift-Gehrels in ZTF images taken with the Oschin 1.2-m Schmidt telescope at Palomar. There is a tail-like morphology with a slightly decreasing apparent brightness visible in images taken on Aug. 7.46 and 13.37 UT, when the r'-band magnitudes were 16.95 and 16.61 (+/- 0.03), respectively, as measured in a 7"-radius aperture. ZTF g'- and r'-band images taken on Aug. 14.41 and 14.44, respectively, show a brighter comet with a fan-like morphology. The fan primarily extends out 16"-20" at position angle spanning 120-310 degrees. The post-outburst brightness (7"-radius aperture) is r' = 13.88 +/- 0.02, indicating an outburst strength of at least 2.7 mag. In addition, the color has slightly blued from g'-r' = 0.67 on Aug. 7 to 0.58 (+/- 0.04) on Aug. 14.
Central Bureau Electronic Telegrams
- Pub Date:
- August 2018