36P/Whipple (0036P)


Type: Periodic Perihelion date: 31 May 2020 Perihelion distance (q): 3.0 Aphelion distance (Q) : 5.2 Period (years): 8.4 Eccentricity (e): 0.27 Inclination (i): 10.0 JPL orbit diagram COBS lightcurve Fred L. Whipple (Harvard College Observatory, Massachusetts, USA) discovered this comet on the edge of a photograph exposed with the 115-cm Metcalf telescope on 15 October 1933. The magnitude was estimated as 13, while a tail was 3 arc minutes long. He confirmed the comet on 21 October. A prediscovery apparition was identified in 1987 by S. Nakano. During September 1925, G. Shajn (Simeis) reported the discovery observations of several minor planets. One of these was designated 1925 QD and it was first photographed on 21 August. The only additional photograph was obtained on 24 August. The brightness was determined as 13.0 on both dates. Nakano did an extensive search through the minor planet database at the Minor Planet Center in Cambridge, Massachusetts. During this search he found that minor planet 1925 QD was in the exact positions expected for 36P/Whipple on those dates, so that observations of this comet existed prior to its discovery in 1933. Cunningham recovered the comet on 1 September 1940 and estimated the magnitude as 15. The comet attained a maximum magnitude of 14 during this apparition and was followed until 22 November 1941. The comet was recovered by H. M. Jeffers (Lick Observatory, California, USA), while using the 36-inch f/5.8 Crossley reflector, on 21 June 1947. Jeffers determined the magnitude as 18.4 and said the comet appeared nearly stellar. The comet attained a maximum magnitude of 14 during September and October of 1948. Elizabeth Roemer (Lick Observatory, California, USA) recovered this comet on 25 May 1955. She estimated the magnitude as 18, and described the comet as "not quite stellar." The comet attained a maximum magnitude of 13 during October. The comet will make one close approach to Jupiter during the 21st century, 0.68 AU on 16 October 2040. Observations (VEMag = visual equivalent magnitude) Date 10x10 mag Error VEmag Coma ' 07-Nov-20 18.77 0.06 18.2 0.4 17-Nov-20 18.80 0.04 18.4 0.4 06-Dec-20 19.09 0.03 18.1 0.4 20-Dec-20 18.93 0.12 18.1 0.4 10-Jan-21 18.5 0.4 17-Jan-21 18.5 0.4 09-Feb-21 19.7 0.4