CBET 4948 & MPEC 2021-F67, issued on 2021, March 22, announce the discovery of an apparently asteroidal object (magnitude ~19.5) on CCD images taken on Feb. 19.5 UT & Mar. 09-5 with the 1.2-m Schmidt telescope at Palomar in the course of the "Zwicky Transient Facility" (ZTF) search program (the object was reported twice by the ZTF survey team as two different objects) . This object has been found to show cometary appearance by CCD astrometrists elsewhere. The new comet has been designated C/2021 D2 (ZTF).
Stacking of 20 unfiltered exposures, 60 seconds each, obtained remotely on 2021, March 15.2 from I89 (iTelescope, Nerpio, Spain) through a 0.32-m f/8.0 reflector + CCD, shows that this object is a comet with a diffuse coma about 8" arcsec in diameter (Observers A. Valvasori, E. Guido).
Stacking of 12 unfiltered exposures, 90 seconds each, obtained remotely on 2021, March 18.2 from Z08 (Telescope Live, Oria) through a 0.7 m f/8 Ritchey Chretien + CCD, shows that this object is a comet with a diffuse coma about 10" in diameter (possibly elongated toward PA 140). (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).
Our confirmation image (click on it for a bigger version; made with TYCHO software by D. Parrott)
MPEC 2021-F67, assigns the following preliminary orbital elements to comet C/2021 D2 (ZTF): T 2022 Feb. 4.17; e= 0.99; Peri. = 125.07; q = 2.94 ; Incl.= 83.84
by Ernesto Guido