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

A. Nakamura image of 43P exposed on 1997 December 4
Copyright © 1997 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)

This CCD image was taken on 1997 December 4.82, using a 0.60-m f/6 Ritchey-Chretien telescope. Two images were overlayed and centered on the comet, which resulted in every star appearing double.


     Max Wolf (Königstuhl Observatory, Heidelberg, Germany) photographically discovered this comet on 1924 December 22.83. He was able to confirm the discovery on December 23.87. The comet was moving slowly through Taurus and was estimated as magnitude 16. A. Kahrstedt (Berlin, Germany) recognised the comet was moving in a short-period orbit by the end of December. The comet steadily faded during the next few weeks and was last seen on 1925 February 14. Thereafter, the orbit was revised, but the comet's large perihelion distance of 2.4 AU and the observation arc of only two months made it obvious that the orbit would not be as precise as desired. The orbital computations also revealed the comet's next return would be very unfavorable and that a close approach to Jupiter in 1936 would add great uncertainty to future predicted returns. The comet was lost.
     No orbit was given for the 1952 return, although the British Astronomical Association Handbook for that year did note that the comet was due to return. Subsequently, Robert G. Harrington's discovery of a comet during the course of the National Geographic Society-Palomar Observatory Sky Survey on 1951 October 4.30 was not immediately suspected as the return of Wolf's comet. Harrington found the comet on a photographic plate and estimated the magnitude as 16. He described the comet as diffuse, with a central condensation, and exhibiting a tail 2 arc minutes long. By early November L. E. Cunningham had computed a short-period orbit and remarked that the comet might be the return of Wolf's lost periodic comet. Several astronomers disagreed, including Antoni Przybylski who computed a definitive orbit for Wolf's comet, ran it through the close encounter with Jupiter in 1936 and produced an orbit with notable differences from that of Harrington's comet. Harrington's comet was recovered in 1957 and was again well observed. M. Kamienski examined the orbit of this comet, as well as the comet of Wolf, and concluded the two were identical.

Historical Highlights

  • The comet has been observed at every return since its rediscovery apparition of 1951-1952. Its most favorable appearances were 1952, when it reached magnitude 12, and 1991, when it reached magnitude 12.5.
  • The comet made its 9th observed return in 1997, which also marked its most favorable return. The comet reached a maximum magnitude slightly brighter than 12.
  • Close approaches to planets: This comet made one close approach to Earth and two close approaches to Jupiter during the 20th century. It makes one close approach to Jupiter during the 21st century. (From the orbital work of Kazuo Kinoshita)
    • 0.13 AU from Jupiter on 1936 June 29
      • decreased perihelion distance from 2.42 AU to 1.45 AU
      • decreased orbital period from 7.56 to 6.20 years
    • 0.72 AU from Jupiter on 1948 January 2
      • increased perihelion distance from 1.45 AU to 1.60 AU
      • increased orbital period from 6.20 to 6.50 years
    • 0.93 AU from Earth on 1951 November 14
    • 0.065 AU from Jupiter on 2019 March 7
      • increased perihelion distance from 1.36 AU to 2.44 AU
      • increased orbital period from 6.13 to 9.01 years

    Additional Images

    R. Ligustri image of 43P exposed on 2003 September 20
    Copyright © 2003 by R. Ligustri (Talmassons, Italy)

    This image was obtained on 2003 September 20.92 UT with the 350/1750 reflector and an SBIG ST9E CCD camera. Three 240-second exposures were combined. The image covers a field measuring 16' by 16'. North is toward the top, while east is to the left.