New Comet C/2021 K1 (ATLAS)

May 31, 2021

CBET 4968 & MPEC 2021-K89, issued on 2021, May 27, announce the discovery of a new comet (magnitude ~17.0) on CCD images taken on May 14.5 UT with the 0.5-m reflector + CCD in the course of the ATLAS-HKO (T05) survey.  The object was originally found by Peter Veres of Minor Planet Center (MPC) as unusually bright among the MPC's isolated tracklet file (ITF) and linked to the detections  from May 22 (F51) and May 14 (T08).  A review of the ATLAS images revealed the cometary nature of this object.

Our confirmation images (click on the images for a bigger version; made with TYCHO software by D. Parrott.

As with the ATLAS observations, this object was reported without comments by Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala on May 22.6 UT (mag 17.6-18.0), submitted as two separate objects on the same night. This object has been found to show cometary appearance also by CCD astrometrists elsewhere after it was posted on the MPC's PCCP webpage. The new comet has been designated C/2021 K1 (ATLAS).

Stacking of 44 unfiltered exposures, 60 seconds each, obtained remotely on 2021, May 27.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 20" arcsecond in diameter and a tail 30" long in PA 245 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

MPEC 2021-K89, assigns the following orbital elements to comet  C/2021 K1 (ATLAS): T 2021 May 4.66; e= 0.80; Peri. =  184.33; q = 2.49 ;  Incl.= 16.27

by Ernesto Guido