C/2021 Y1 (ATLAS)

DEPARTED

Type: Hyperbolic Perihelion date: 30 April 2023 Perihelion distance (q): 2.0 Aphelion distance (Q) : n/a Period (years): n/a Eccentricity (e): 1.00 Inclination (i): 77.2 JPL orbit diagram COBS lightcurve A 19th magnitude object was discovered in images taken with the 0.5m Schmidt at Mauna Loa on 26 December 2021 by the ATLAS (Asteroid Terrestrial-impact Last Alert System) team. Follow-up observations by astrometrists showed cometary activity. Pre-discovery images taken by M Holbroook at Pleasant Groves Observatory on two days in November were then linked to the comet. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 29-Aug-22 17.4 0.4 08-Sep-22 16.9 0.4 03-Oct-22 16.9 0.4 27-Oct-22 15.96 0.02 16.1 0.4 14-Nov-22 15.1 0.4 23-Nov-22 15.10 0.03 15.1 0.4 29-Nov-22 15.10 0.02 14.5 0.6 17-Jan-23 15.51 0.01 14.6 0.9 16-Feb-23 13.1 0.9