CBET 5029 & MPEC 2021-R98 , issued on 2021, September 06, announce the discovery of a new comet (magnitude ~17) on CCD images taken on August 29.6 UT with a 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. The new comet has been designated P/2021 Q5 (ATLAS).
Stacking of 58 unfiltered exposures, 30 seconds each, obtained remotely on 2021, September 03.1 from G18 (ALMO Observatory, Italy) through a 0.30-m f/4 reflector + CCD, shows that this object is a comet with a compact coma about 8" arcsec in diameter and a tail 10" long in PA 270 (Observers A. Valvasori & E. Guido).
MPEC 2021-R98, assigns the following preliminary orbital elements to comet P/2021 Q5 (ATLAS): T 2021 August 30.34; e= 0.61; Peri. = 180.81; q = 1.23 ; Incl.= 10.72.
by Ernesto Guido