G A R Y   W.   K R O N K ' S   C O M E T O G R A P H Y


Past, Present, and Future Orbits by Kazuo Kinoshita

C. T. Kowal photo of 158P exposed on 1979 July 24
Copyright © 1979 by Charles T. Kowal

DISCOVERY IMAGE: This photo was obtained by C. T. Kowal (Palomar Observatory, California, USA) on 1979 July 24.21. The comet trailed during the exposure. North is up, while east is to the left. (Special thanks to Charles T. Kowal for allowing me to use this image).


     Charles T. Kowal (Palomar Observatory, California, USA) found images of this comet in late August of 1979 on photographic plates exposed one month earlier with the 1.20-m Schmidt telescope. The earliest image was obtained on July 24.21, while two additional images were obtained on July 25.21 and July 27.22.
     This comet was discovered by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) project on 2001 September 12.26 and was reported as a minor planet of magnitude 19.1. It was subsequently found on additional LINEAR images obtained on August 25. After the orbit was well established, a prediscovery image was found on a plate exposed with the 1.2-m Schmidt at Siding Spring (Australia) on 1990 September 23.

Historical Highlights

  • Apparition of 1979: Three images of the comet were found on plates exposed over a period of four days, but these images were not found until more than a month had passed. Two days after the initial announcement, B. G. Marsden calculated a parabolic orbit with a perihelion date of 1978 January 23.28 and provided an ephemeris covering the period of August 15 to September 24. He noted, "It is rather probable that the comet is a short-period one." Marsden added that if the comet was periodic, the ephemeris could be uncertain by up to one degree. No further observations were acquired.
  • Apparition of 2002: This "minor planet" was observed off and on for the next two years, following its discovery. Then on 2003 November 26.4. A. E. Gleason (Kitt Peak Observatory, Arizona, USA) imaged the object with the 0.9-m Spacewatch reflector and noted a condensed coma 6 arc seconds across that exhibited a tail extending 18 arc seconds toward PA 265°. The Minor Planet Center made a request for confirmation and J. Young (Table Mountain Observatory, California, USA) obtained a CCD image on November 27 which revealed a coma 4 arc seconds across and a broad, faint tail extending 12 arc seconds toward PA 265°. Knowing that this was now a comet that should be detectable throughout its orbit, a search was made for older images. Soon images were reported at Siding Spring from 1990 September 23 and at Palomar Observatory from 1993 November 11. On December 2, S. Nakano linked this comet to the lost comet reported by Kowal back in 1979.
  • Additional Images

    Siding Spring image of 158P exposed on 1990 September 23
    Copyright © 1990 by Siding Spring Observatory

    This image is a prediscovery image found after the orbit had been established. It was obtained at Siding Spring (Australia) on 1990 September 23. The image was found and subsequently measured by R. Stoss. The comet is the small, round, and diffuse object in the center.