53P/van Biesbroeck

Past, Present, and Future Orbits by Kazuo Kinoshita

Copyright © 2003 by H. Mikuz (Crni Vrh Observatory, Slovenia) This false-color image was taken by Hermann Mikuz on 2003 May 25.925 UT, using a 0.60-m f/3.3 Deltagraph telescope. Mikuz used a V filter and the exposure time was 90 seconds. Discovery      During an unsuccessful attempt to recover the asteroid 1953 GC, George van Biesbroeck (Yerkes Observatory, Wisconsin, USA) discovered this comet on a 16-minute exposure obtained with the 24-inch reflector on 1954 September 1.18. He estimated the magnitude as 14.5, and described the comet as round, well condensed, and 8 arc seconds across. The comet was also present on a 16-minute exposure obtained with the same telescope on September 1.19. Historical Highlights The first orbit was calculated by Eugene Karl Rabe (Cincinnati Observatory, Ohio, USA). He took three positions from the period of September 1 to 7 and calculated both parabolic and elliptical orbits, which were first published on 1954 September 22. For the parabolic orbit, the perihelion date was determined as 1954 January 1.57. The elliptical orbit did not fit the positions as well as the parabolic, but still left small residuals. The orbital period was determined as 7.78 years. Leland E. Cunningham (Leuschner Observatory, Berkeley, California, USA) published an improved orbit on October 15, which used positions obtained through September 30. This gave the perihelion date as 1954 February 11.77 and the period as 14.1 years. Cunningham remarked that the comet had the potential of undergoing strong perturbations from Jupiter and Saturn, "but no close approach to either planet has occurred in recent years." One of the most recent calculations came from Kenji Muraoka (Japan) in 1990. Using positions from multiple apparitions, he found the 1954 orbit had a perihelion date of February 20.76 and a period of 12.43 years. Additional Images Copyright © 2003 by R. Ligustri (Talmassons, Italy) This image was obtained on 2003 August 26.80 UT with the 350/1750 reflector and an SBIG ST9E CCD camera. Two 120-second exposures were combined. The image covers a field measuring 16' by 16'. North is toward the top, while east is to the left. Copyright © 2003 by R. Ligustri (Talmassons, Italy) This image was obtained on 2003 August 31.81 UT with the 350/1750 reflector and an SBIG ST9E CCD camera. Two 120-second exposures were combined. The image covers a field measuring 16' by 16'. North is toward the top, while east is to the left. cometography.com