Comets - 117P/Helin-Roman-Alu - 0117P
Type Periodic PPerihelion Date 26 March 2014 Perihelion Distance (q) 3.1 Aphelion Distance (Q) 5.1 Period (Years)   8.3 Eccentricity (e)   0.25 Inclination (i)   8.7 Click for NASA orbit diagram  
Hills Observatory: 1 January 2013 to 15 September 2018
COMETS COMETS
DEEP SKY DEEP SKY
The comet was discovered by Eleanor F. Helin, Brian P. Roman, and Jeff Alu (Palomar Observatory, California, USA) on images obtained with the 0.46-m Schmidt telescope on 1989 October 2. They described it as diffuse with some condensation, and estimated the magnitude as 17.5 and confirmed the comet on October 5 and 6. James V. Scotti (Steward Observatory, Kitt Peak, USA) detected the comet with a 0.91-m telescope on 1993 January 24, when it was near aphelion. The magnitude was given as 21.2 and the comet was then 5.25 AU from the sun. This showed the comet was visible throughout its orbit. It is a Quasi-Hilda comet. Date 10x10 mag Error Kphot mag Coma ' 19 Jan 13 17.03 0.03 16.8 0.2 29 Jan 13 16.68 0.03 16.1 0.3 4 Mar 13 16.52 0.02 16.2 0.2 17 Mar 13 16.23 0.00 15.8 0.3 3 Apr 13 15.90 0.02 15.1 0.4 17 Apr 13 15.22 0.02 14.4 0.5 2 May 13 14.88 0.01 14.1 0.5 27 May 13 15.20 0.05 14.5 0.3 9 Jun 13 15.40 0.01 14.5 0.4 24 Jun 13 15.46 0.08 13.3 0.3 5 Jul 13 15.64 0.04 14.5 0.3 24 Jul 13 15.58 0.04 14.5 0.3 10 Aug 13 15.55 0.02 14.5 0.4 16 Apr 14 15.50 0.04 13.9 0.2 21 May 14 15.37 0.01 14.4 0.3 8 Jun 14 15.20 0.02 14.2 0.3 2 Jul 14 14.88 0.02 13.5 0.3 16 Jul 14 14.71 0.02 13.3 0.3 26 Jul 14 14.59 0.02 13.3 0.3 5 Aug 14 14.56 0.03 13.1 0.4 20 Aug 14 14.65 0.04 13.1 0.4 14 Sep 14 15.10 0.02 13.3 0.4 27 Sep 14 15.17 0.01 13.4 0.7 7 Oct 14 15.28 0.03 13.6 0.5 20 Oct 14 15.42 0.02 13.4 0.4 27 Oct 14 15.47 0.03 13.8 0.6 17 Nov 14 15.65 0.03 14.1 0.5 20-Jun-15 16.86 0.05 15.8 0.2 04-Jul-15 16.77 0.16 16.2 0.2 19-Jul-15 16.73 0.05 16.0 0.2 09-Aug-15 16.60 0.03 14.7 0.2 15-Aug-15 16.66 0.04 15.6 0.3 22-Aug-15 16.57 0.01 15.6 0.3 07-Sep-15 16.51 0.02 15.4 0.2 16-Sep-15 16.36 0.01 15.4 0.3 23-Sep-15 16.30 0.01 15.2 0.3 07-Oct-15 16.18 0.01 15.0 0.4 18-Oct-15 16.13 0.02 15.0 0.3 31-Oct-15 16.31 0.03 15.2 0.4 09-Nov-15 16.33 0.01 15.2 0.3 16-Nov-15 16.41 0.02 14.7 0.2 03-Dec-15 16.62 0.02 15.3 0.3 13-Dec-15 16.76 0.01 15.3 0.4 30-Aug-16 18.22 0.27 15.4 0.2 15-Sep-16 18.04 0.06 15.7 0.2 28-Sep-16 18.06 0.06 17.0 0.2 29-Oct-16 17.84 0.04 17.3 0.2 10-Nov-16 17.67 0.18 16.1 0.3 23-Nov-16 17.39 0.03 16.4 0.3 19-Dec-16 17.81 0.02 16.7 0.3 26-Dec-16 17.93 0.14 15.6 0.2
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