162P/Siding Spring (0162P)

Type: Periodic Perihelion date: 7 December 2020 Perihelion distance (q): 1.3 Aphelion distance (Q) : 4.9 Period (years): 5.4 Eccentricity (e): 0.58 Inclination (i): 27.6 JPL orbit diagram COBS lightcurve The Near Earth Object 2004 TU12 was discovered on 10 October 2004 by the Siding Spring Survey (Australia), announced on MPEC 2004-T55 and classified as an amor object. On 12 November, J. Lacruz at the La CaƱada Observatory noticed a faint trace to the north-east originating at the neo and thought it could be a comet. Stacking many images the trace was visible as a straight tail moving as a whole with the nucleus. The object was reclassified as 162P/Siding Spring, but debate continues concerning the nature of the tail. Computer models suggest that the tail cannot be ionised gas and the dust has physical and dynamical properties unlike other comet dust tails. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 18-Aug-15 16.96 0.04 15.3 0.2 27-Aug-15 16.58 0.02 16.3 0.2 14-Sep-15 17.20 0.05 16.7 0.2 27-Sep-15 17.62 0.31 17.3 0.2 21-Oct-15 17.92 0.26 16.5 0.2 08-Nov-15 17.05 0.04 17.0 0.2 17-Nov-15 17.08 0.03 16.4 0.2 09-Dec-15 17.08 0.01 17.0 0.2 18-Dec-15 17.63 0.02 17.5 0.2 04-Feb-16 17.73 0.02 17.6 0.2 11-Feb-16 18.03 0.03 17.9 0.2 28-Feb-16 17.65 0.05 17.2 0.2 28-Mar-16 18.71 0.11 18.4 0.2 12-Apr-16 18.33 0.11 18.1 0.2 02-May-16 19.02 0.29 18.9 0.2 17-Nov-20 16.36 0.03 16.1 0.4 06-Dec-20 16.39 0.05 15.6 0.4 14-Dec-20 15.99 0.05 15.5 0.4 10-Apr-21 18.1 0.4