C/2017 T2 (PANSTARRS)

Type: Periodic Perihelion date: 4 May 2020 Perihelion distance (q): 1.6 Aphelion distance (Q) : 10,070 Period (years): 357,348 Eccentricity (e): 1.00 Inclination (i): 57.2 JPL orbit diagram COBS lightcurve A 20th magnitude comet was discovered in PanSTARRS 1 images taken with the 1.8m Ritchey-Chretien on 2 October 2017. There were pre-discovery PanSTARRS images from 15 September. It had been posted on the PCCP as P10E7lu. JJ Gonzalez picked it up visually in March 2019, roughly in line with the magnitude expected if the electronic observations are corrected for aperture. He recovered it after solar conjunction at the end of July, when he estimated it at 9th magnitude. Visual magnitudes have generally been brighter than those reported from images, and visual observers see a larger coma diameter. However, subsequent observations have not confirmed the early visual estimates, which lie much above the mean light curve. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 21-Nov-17 18.85 0.16 18.5 0.2 13-Dec-17 18.89 0.06 18.7 0.2 19-Dec-17 18.83 0.07 18.5 0.2 11-Jan-18 18.61 0.01 18.5 0.2 04-Feb-18 18.66 0.09 18.6 0.2 05-Feb-18 18.78 0.09 18.5 0.2 13-Feb-18 18.60 0.11 18.6 0.2 12-Oct-18 16.45 0.02 16.1 0.4 02-Nov-18 16.15 0.01 15.1 0.6 08-Nov-18 16.05 0.03 15.1 0.4 15-Nov-18 15.98 0.01 15.5 0.5 28-Nov-18 15.84 0.01 15.4 0.4 03-Dec-18 15.84 0.01 15.3 0.4 08-Dec-18 15.84 0.01 15.3 0.4 15-Dec-18 15.84 0.02 15.2 0.4 27-Dec-18 15.81 0.01 15.3 0.4 01-Jan-19 15.81 0.01 15.4 0.3 09-Jan-19 15.92 0.01 15.4 0.4 03-Sep-19 14.36 0.01 12.9 0.8 08-Sep-19 14.28 0.01 13.0 0.8 27-Sep-19 13.97 0.01 12.2 1.0 04-Oct-19 13.88 0.01 12.1 1.1 29-Oct-19 13.37 0.01 11.3 1.4 03-Nov-19 13.35 0.01 11.1 1.7 23-Nov-19 12.93 0.01 10.4 1.9 28-Nov-19 12.78 0.02 9.9 2.3 19-Dec-19 12.03 0.01 9.3 2.8 26-Dec-19 12.52 0.01 9.5 3.5 31-Dec-19 12.43 0.01 9.4 3.4 14-Jan-20 12.80 0.01 10.1 3.4 24-Jan-20 12.74 0.01 9.7 3.2 22-May-20 12.69 0.04 8.5 6.9