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93P/Lovas 1

Past, Present, and Future Orbits by Kazuo Kinoshita

G. Rhemann image of 93P exposed on 1998 December 9
Copyright © 1998 by G. Rhemann

This image was taken by Gerald Rhemann on 1998 December 9.79. He used a 25.4-cm, Schmidt camera. Exposure time was 10 minutes and the photographic emulsion was hypered TP6415. The webmaster has cropped the image to save space. (Thanks to Gerald Rhemann for permission to use this image.


     Miklos Lovas (Konkoly Observatory, Hungary) found an image of this comet on a photographic plate exposed on 1980 December 5.06. He described it as diffuse, with a condensation. The magnitude was estimated as 17. The comet was officially announced by the International Astronomical Union Circular no. 3547 on December 8. Interestingly, IAU Circular 3551 announced on December 15, "No confirmation or denial of the existence of this object has been reported." This statement prompted astronomers to send their observations to the appropriate authorities. Lovas said he had photographed the comet again on December 9.01, and T. Seki (Geisei, Japan) had photographed it on December 9.77. The magnitude was still given as 17 and there was still no report of a tail.
     An independent discovery was made by C. Kowal (Palomar Observatory, California, USA), who detected the comet on a photograph exposed on December 14.46. He confirmed the find on December 15.49. Kowal was using the 1.2-m Schmidt telescope and the comet's magnitude was again given as 17.

Historical Highlights

  • Brian G. Marsden announced on 1981 January 2 that, "The orbit of this comet cannot be reliably determined from the three existing accurate positions (IAUC 3554-3555), but it appears that the comet may be a short-period one." He added that observations were urgently needed. Observations from January 6 and 9 were subsequently received and Marsden was able to finally compute an orbit, albeit a parabolic one. This indicated a perihelion date of 1980 September 23.5, and a perihelion distance of 1.47 AU. Marsden's early suggestion that the comet moved in a short-period orbit was finally confirmed as February began, after receiving observations from late January. This adjusted the perihelion date to 1980 September 3.6, the perihelion distance as 1.675 AU, and the orbital period as 9.07 years.
  • The comet was recovered on 1989 July 7.77 by Seki. He found it with a 0.60-m reflector and estimated the magnitude as 17.5. He confirmed the recovery on July 13.77. The precise positions indicated the prediction required a correction of -0.22 day. The comet slowly brightened and by November and December it was brighter than magnitude 13.
  • The comet last passed perihelion on 1998 October 14. It was recovered on 1998 June 17.44 at Whipple Observatory (Mt. Hopkins). Observations there and at Steward Observatory (Kitt Peak, Arizona, USA) indicated the magnitude was between 17.5 and 18. The comet was widely observed by both professional and amateur astronomers as it rose to about 13th magnitude at the end of 1998 and early in 1999.
  • Additional Images

    H. Mikuz image of 93P exposed on 1998 August 24
    Copyright © 1998 by Herman Mikuz (Crni Vrh Observatory, Slovenia)

    This false-color image was obtained on 1998 August 24.01 UT with a 36-cm, f/6.7 Schmidt-Cassegrain telescope, V filter, and CCD. Exposure time was 5 minutes. (The image was cropped by the webmaster and converted to black and white to save space.)