We performed follow-up measurements of this object while it was still on the PCCP webpage.
Stacking of 8 unfiltered exposures, 90 seconds each, obtained remotely on 2020, May 04.3 from X02 (Telescope Live, Chile) through a 0.6-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 5" in diameter.
MPEC 2020-J37, assigns the following preliminary parabolic orbital elements to comet C/2020 J1 (SONEAR): T 2021 Apr. 15.73; e= 1.0; Peri. = 344.44; q = 3.25; Incl.= 142.16
By Ernesto Guido & Adriano Valvasori