Comets - 137P (Shoemaker-Levy) - 0137P
Type Periodic Perihelion Date 13 December 2018 Perihelion Distance (q) 1.9 Aphelion Distance (Q) 7.1 Period (Years)   9.6 Eccentricity (e)   0.57 Inclination (i)   4.9 Click for NASA orbit diagram
Hills Observatory: 1 January 2013 to 16 November 2018
COMETS COMETS
DEEP SKY DEEP SKY
During the last half of November of 1990 Carolyn S. Shoemaker (Palomar Observatory, California, USA) discovered images of an asteroidal object on plates taken on 25 October, 13 and 15 November. The magnitude was estimated as 17 on 25 October and 17.7 on 13 November. Prediscovery images were then located on plates exposed at Palomar Observatory by H. E. Holt, H. R. Holt, C. M. Olmstead, and J. A. Brown on 17 and 20 September.  The magnitude was determined as 17.6. Gareth V. Williams took the available positions and computed an elliptical orbit with a perihelion date of 25 September 1990 and an orbital period of 9.27 years. He said the orbit indicated this was a Jupiter-crossing object. The object was given the minor planet designation of 1990 UL3. Brian Skiff (Lowell Observatory, Arizona, USA) announced that CCD images obtained with a 1.1-m reflector on 7 December revealed a straight tail extending 29 arc seconds toward PA 67°. Before this announcement, S. Larson and Levy (University of Arizona) obtained CCD images of the comet with the Catalina 1.5-telescope on 19 December and detected a tail extending 28 arcseconds toward PA 58°. Thus, the "minor planet" proved to be a comet. Date 10x10 mag Error Kphot mag Coma ' 14-Jul-18 17.81 0.02 17.8 0.2 04-Aug-18 17.12   0.02   17.1   0.2 17-Aug-18 16.75   0.06 16.3 0.3 31-Aug-18 16.73 0.02 16.7 0.2 07-Sep-18 16.91 0.01 16.1 0.3 29-Sep-18 17.25 0.06 17.0 0.2 10-Oct-18   17.44   0.02   17.4   0.2 11-Nov-18   17.92   0.18 17.4 0.3