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Past, Present, and Future Orbits by Kazuo Kinoshita

C. T. Kowal image of 69P exposed on 1976 December 13
Copyright © 1976 by Charles T. Kowal (Palomar Observatory, California, USA)

RECOVERY IMAGE: Charles T. Kowal obtained this photograph on 1976 December 13.27, using the 122-cm Schmidt telescope. It is an 8-minute exposure on Kodak 103a-O film. The comet's magnitude was estimated as 16. This is most likely the "B" component observed during early 1916. North is up and east is left. (Special thanks to Charles T. Kowal for allowing me to use this image.)


     Clement J. Taylor (Capetown, South Africa) discovered this comet in Orion on 1915 November 24. It passed closest to Earth on December 31 (0.6486 AU) and arrived at perihelion on 1916 January 31.

Historical Highlights

  • The comet was first recognised at periodic shortly after mid-December 1915, when Neubauer and Jeffers (Berkeley Astronomical Department, California, USA) determined the orbital period as 5.30 years. Less than three weeks later astronomers had revised this value to 6.29 years, and after the comet was last detected on 1916 May 28, the period was revised to 6.37 years.
  • On 1916 February 3 and 4, George van Biesbroeck (Yerkes Observatory, Wisconsin, USA) noted that the comet's nucleus appeared elongated. By the 10th, E. E. Barnard (Yerkes Observatory) reported, "two perfectly distinct comets whose nebulosity mingled." Barnard added, "The south one [A] was the brighter and had a small bright nucleus; the north one [B] less definite." Nucleus A was not seen after 1916 March 23.
  • Jeffers investigated the motion of the comet and predicted it would return to perihelion on 1922 June 13. He added, "The position with respect to the Sun will be unfavorable for observation at that time. Some months before and after perihelion the comet will be better situated with respect to the Sun, though it will be faint." Nevertheless, the comet was not recovered.
  • Various computations revealed the comet would next arrive at perihelion sometime between 1928 October 21 and 28. Once again, the comet failed to be recovered. Interestingly, Karl Reinmuth (Heidelberg Königstuhl Observatory) discovered a comet during a routine asteroid survey on 1928 February 22. As March began, astronomers realized the comet was periodic and several suggested it was identical to Taylor's comet, citing that it passed close to Jupiter during 1925. As the comet continued to be observed, the orbit was revised, and astronomers realized the Jupiter encounter could not have placed comet Taylor into the orbit currently occupied by comet Reinmuth (later known as 30P/Reinmuth 1).
  • Additional attempts were made to link this comet to other comets. Periodic comet Arend-Rigaux was discovered during 1951 February. As astronomers determined its orbit they initially noted a similarity to Taylor's comet. In 1954, V. A. Bronshten suggested that one part of comet Taylor had returned as Periodic comet Arend-Rigaux, while the other part returned as D/1952 B1 (Harrington-Wilson). All of these ideas were proven incorrect as the 1950s progressed.
  • N. A. Belyaev and V. V. Emel'yanenko provided a prediction for the comet's 1976 return. On 1977 January 25, Charles Kowal (Palomar Observatory, California, USA) was examining plates exposed for the comet when he found images obtained on 1976 December 13 and 14. The measured positions indicated the prediction of Belyaev and Emel'yanenko needed a correction of only -1.4 days. They also indicated this was nucleus B, but searches for nucleus A never revealed anything. The comet was followed until April 16. The comet was further observed at its next returns in 1984 and 1990.
  • The comet passed perihelion on 1997 December 12 (1.948 AU) and passed closest to Earth (0.9923 AU) on 1998 January 14. Although the comet was not expected to exceed magnitude 18, observers during January found the comet near magnitude 12.
  • Additional Images

    A. Nakamura image of 69P exposed on 1997 December 4
    Copyright © 1997 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)

    This CCD image was taken on 1997 December 4.77, 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.

    Stefano Sposetti image of 69P exposed on 1998 March 18
    Copyright © 1998 by Stefano Sposetti

    This image was taken by Stefano Sposetti on 1998 March 18.9. He used a 0.20-m f/6.3 Celestron and a Hi-SIS22 CCD camera. The image is composed of 60 30-second exposures. North is up and east is left.