THE ASTRONOMER Electronic Circular No 3728 2022 Aug 20 16.06UT Ed:Guy M Hurst, 16,Westminster 
Close, Kempshott Rise, Basingstoke, Hants, RG22 
4PP,England.Telephone/FAX(01256)471074Int:+441256471074 INTERNET: GUY@TAHQ.DEMON.CO.UK 
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SMALL OUTBURST OF COMET 73P
Michael S. P. Kelley (U. Maryland), Tim Lister (Las Cumbres Observatory), Carrie E. Holt (U. Maryland) 
on behalf of the LCO Outbursting: (ATEL 15560) we report on an apparent outburst of comet 
73P/Schwassmann-Wachmann 3 in Las Cumbres Observatory (LCO) 1-meter telescope data taken as 
part of the LCO Outbursting Objects Key Project. Photometry measured in a 5" radius aperture was 
g=14.590.03 and r=14.060.03 mag at 2022 Aug 17.97 UTC (PS1 photometric system). The comet 
brightened to g=14.260.02 and r=13.690.05 mag by the next detection at Aug 18.27 UTC, resulting in 
an apparent outburst strength of -0.350.03 mag in our photometric aperture. The outburst is 
confirmed in follow[1]up observations taken Aug 18.98 UTC with g=14.270.02 and r=13.680.02 mag. 
At the time of the first outburst detection, the comet was 0.98 au from the Sun, 1.09 au from the 
Earth, and at a Sun-target-observer angle of 58 deg. 
Guy M Hurst
