105P/Singer Brewster (0105P)


Type: Periodic Perihelion date: 9 August 2018 Perihelion distance (q): 2.0 Aphelion distance (Q) : 4.9 Period (years): 6.5 Eccentricity (e): 0.41 Inclination (i): 9.2 JPL orbit diagram COBS lightcurve Stephen Singer-Brewster discovered this comet on two plates exposed by D. Schneeberger, E. Burr and himself on 3 May 1986 with the 0.46-m Schmidt telescope at Palomar Observatory. The images were obtained in the course of the International Near-Earth Asteroid Survey under the direction of E. F. Helin. The magnitude was estimated as 15 and the comet was described as "diffuse and only slightly condensed." Another image of the comet was found on plates exposed with the same telescope the next evening by Carolyn S. and Eugene M. Shoemaker. The Shoemaker images revealed a possible faint tail to the northeast. James V. Scotti (Lunar and Planetary Laboratory) recovered this comet on 1 April 1992, while using the Spacewatch telescope at Kitt Peak. The precise position indicated the prediction required a correction of -0.84 day. Scotti described the comet as magnitude 20.4. He added that it was slightly diffuse, with a coma 8 arc seconds across. The comet was next expected to arrive at perihelion on 6 April 1999. It was recovered on 13 February 1999 by S. M. Larson and C. W. Hergenrother (University of Arizona, Catalina Station, USA), using the 1.5-m reflector and a CCD camera. Kazuo Kinoshita has examined the orbital history of this comet. The comet passed 0.3765 AU from Jupiter on 5 August 1976, which made fairly significant alterations in the orbit. Most notable was a change in the perihelion distance from 2.27 AU to 1.95 AU and a change in the orbital period from 6.70 years to 6.29 years. The comet will undergo only very minor changes in its orbit until 6 August 2059, when a passage of 0.4072 AU from Jupiter will again change the orbit to some degree. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 13-Mar-18 17.85 0.02 17.2 0.4 20-Mar-18 17.59 0.07 17.0 0.4 16-May-18 17.71 0.01 16.8 0.4 02-Jun-18 17.90 0.05 15.6 0.5 14-Jun-18 18.08 0.08 17.4 0.3