C/2013 US10 (Catalina)

DEPARTED

Type: Hyperbolic Perihelion date: 15 November 2015 Perihelion distance (q): 0.8 Aphelion distance (Q) : n/a Period (years): n/a Eccentricity (e): 1.00 Inclination (i): 148.9 JPL orbit diagram COBS lightcurve A 19th magnitude object discovered during the course of the Catalina Sky Survey with the 0.68-m Schmidt on 31 October 2013 turned out to be a comet. The asteroidal orbit seemed very odd, with period of 6.1 years and perihelion at 0.4 au, although it made no nearby passes to Jupiter, and the asteroid had a fairly bright absolute magnitude. The orbit had a MOID with respect to Earth of 0.54 au. The comet was very distant from the Sun, being 8.3 au away at discovery and still 3.9 au away in mid December 2014. It was slightly fainter than expected when it was observed visually after solar conjunction in April 2015 and the rate of brightening seemed to be slowing, however there was no significant change with additional observations in June, which put the comet at around 10.5. It was 9th magnitude by July and had reached 6.5 by the end of August. It was picked up after perihelion by Juan Jose Gonzalez on 22 November at 6th magnitude. By early February the comet was fading rapidly and becoming a difficult object, although well placed at high northern declination. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 16-Nov-13 17.83 0.29 17.6 0.2 23-Nov-13 18.21 0.10 17.8 0.2 12-Dec-13 18.06 0.08 17.9 0.2 17-Dec-13 18.14 0.12 18.0 0.2 16-May-14 16.57 0.04 16.3 0.2 08-Jun-14 16.24 0.15 16.1 0.2 14-Jun-14 16.18 0.06 16.1 0.2 03-Jul-14 15.93 0.02 15.6 0.2 12-Jul-14 15.67 0.11 18-Jul-14 15.57 0.03 15.3 0.2 21-Jul-14 15.57 0.02 15.2 0.2 26-Jul-14 15.55 0.02 15.1 0.3 30-Jul-14 15.53 0.02 15.1 0.3 03-Aug-14 15.36 0.02 14.9 0.3 06-Aug-14 15.38 0.02 14.9 0.3 18-Aug-14 15.15 0.04 14.6 0.3 24-Aug-14 15.20 0.05 14.3 0.2 27-Aug-14 15.10 0.01 14.5 0.4 12-Sep-14 14.87 0.01 14.3 0.4 15-Sep-14 14.89 0.02 14.2 0.4 20-Sep-14 14.85 0.02 14.2 0.5 29-Sep-14 14.99 0.03 14.2 0.4 02-Oct-14 14.94 0.02 14.2 0.3 10-Oct-14 14.92 0.01 14.2 0.5 15-Oct-14 14.84 0.03 14.0 0.5 19-Oct-14 14.90 0.02 14.1 0.5 22-Oct-14 14.95 0.03 14.1 0.5 25-Oct-14 14.91 0.05 14.1 0.5 28-Oct-14 14.95 0.02 14.2 0.5 05-Nov-14 14.88 0.02 14.1 0.4 10-Nov-14 14.87 0.02 14.0 0.4 17-Nov-14 14.87 0.01 14.1 0.5 20-Nov-14 14.87 0.03 14.1 0.4 24-Nov-14 14.87 0.02 14.1 0.4 27-Nov-14 14.90 0.03 14.1 0.4 30-Nov-14 14.82 0.03 13.8 0.4 03-Dec-14 14.83 0.01 13.9 0.3 08-Dec-14 14.82 0.03 14.1 0.4 20-Apr-15 13.66 0.02 12.2 0.7 02-May-15 13.59 0.04 11.7 0.4 27-May-15 13.15 0.02 10.7 0.7 04-Jun-15 13.09 0.01 10.6 1.2 07-Jun-15 12.98 0.01 10.3 1.1 10-Jun-15 12.92 0.02 10.1 1.5 13-Jun-15 12.92 0.02 10.0 1.4 20-Jun-15 12.66 0.01 9.6 1.9 26-Jun-15 12.57 0.03 9.2 1.9 19-Jul-15 11.94 0.03 8.4 1.5 22-Jul-15 11.53 0.07 8.1 2.9 26-Jul-15 11.93 0.01 8.5 3.2 27-Jul-15 11.96 0.02 8.5 3.4 08-Aug-15 11.14 0.01 7.8 2.2 09-Dec-15 10.04 0.04 6.8 4.2 13-Dec-15 10.17 0.02 7.1 5.4 14-Dec-15 10.06 0.03 6.9 6.3 17-Dec-15 10.36 0.00 7.3 5.5 19-Dec-15 10.32 0.05 7.2 6.2 21-Dec-15 10.07 0.18 6.9 6.7 24-Dec-15 10.56 0.01 7.5 7.3 03-Feb-16 11.70 0.01 8.6 6.2 06-Feb-16 11.54 0.01 8.4 5.7 20-Feb-16 12.48 0.01 9.2 4.5 25-Feb-16 12.72 0.02 9.6 3.4 14-Mar-16 13.02 0.01 9.7 2.2 21-Mar-16 13.33 0.01 10.1 2.1 13-Apr-16 13.91 0.01 10.6 1.2 26-Aug-16 15.77 0.07 12.6 0.6 07-Oct-16 16.29 0.01 13.7 0.7 01-Nov-16 16.49 0.07 14.3 0.3 10-Nov-16 16.10 0.03 13.3 0.5 19-Dec-16 16.67 0.03 14.4 0.5 27-Dec-16 16.89 0.07 14.8 0.5 04-Jan-17 17.05 0.04 15.1 0.3 17-Jan-17 17.31 0.01 15.7 0.4 14-Feb-17 17.78 0.06 14.8 0.2