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118P/Shoemaker-Levy 4

Past, Present, and Future Orbits by Kazuo Kinoshita

A. Nakamura image of 118P obtained on 1997 January 11
Copyright © 1997 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)

The CCD image was taken on 1997 January 11, using a 0.60-m f/6 Ritchey-Chretien telescope.


     C. S. Shoemaker, E. M. Shoemaker, and D. H. Levy (Palomar Observatory, California, USA) discovered this comet in Virgo on films exposed on February 9.46 with the 0.46-m Schmidt telescope. The comet was described as diffuse and magnitude 17. There was also a short tail extending toward the west.

Historical Highlights

  • Daniel W. E. Green published the first parabolic orbit for this comet on February 13, using positions obtained at Palomar and other observatories. It indicated a perihelion date of 1990 October 8. After the arrival of further observations during the next couple of weeks, the comet was officially announced as a short-period comet on February 26, with Brian G. Marsden having computed an elliptical orbit with a perihelion date of 1990 July 19 and an orbital period of 6.82 years.
  • With the comet having passed perihelion seven months prior to discovery, it steadily faded after February. The final observation was obtained on April 19 at Oak Ridge Observatory. Shortly thereafter a revised orbit indicated a period of 6.53 years.
  • S. Nakano predicted the comet would next arrive at perihelion on 1997 January 12. The prediction enabled James V. Scotti to recover the comet on 1995 June 22.45. Scotti used the 0.9-m Spacewatch telescope at Kitt Peak. The comet was described as stellar with a magnitude of 21.9. The Scotti's position indicated the predicted perihelion date was only in error by 0.6 day.
  • The 1997 apparition was rather favorable as the comet became brighter than magnitude 13 from 1996 November through 1997 March.
  • cometography.com