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 33P exposed on 2001 March 21
Copyright © 2001 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan)

This CCD image was taken on 2001 March 21.69, using a 0.60-m f/6 Ritchey-Chretien telescope. The comet is virtually stellar near the center of the image, with only a trace of diffuseness around its edges.


     This comet was discovered by Zaccheus Daniel (Halsted Observatory, Princeton University, New Jersey, USA) on 1909 December 7.10. He said the comet was about 9th magnitude and was visible in a small telescope, with a nucleus of magnitude 13. He added that it was slowing moving northward.

Historical Highlights

  • Apparition of 1909 (discovery): The comet had already passed perihelion when discovered and was actually found on the day of its closest approach to Earth. Therefore, it was most likely near its maximum brightness when found. Nevertheless, magnitude estimates of 9.2 to 9.5 were reported by other observers up until mid-December and this faded to 10-11 by mid-January of 1910. The final observation of this comet was obtained photographically by Wolf. The 60-minute exposure began on April 11.97 and ended on April 12.01. Wolf said the comet was 1 arc minute across and fainter than was 1P/Halley on the recovery photograph taken on 1909 September 12. He had then remarked that the magnitude of 1P/Halley was 16. Wolf said he obtained two 1 hour 20 minute exposures on the night of May 12/13. He noted, "I could not see it with certainty on the plates."
  • Apparition of 1937: Despite a careful examination of the orbit of this comet by Alexander D. Dubiago following its discovery apparition, searches during the predicted returns of 1916, 1923, and 1930, revealed nothing. During the summer of 1936, S. Kanda suggested to Hidewo Hirose (Tokyo, Japan) that a search ephemeris for the 1937 apparition should be computed. Hirose took Dubiago's orbit for the unobserved 1923 apparition and computed the perturbations from Jupiter for the period of 1923 to 1936. He noted that the upcoming return of 1937 would be favorable for recovery, and predicted a perihelion date of 1937 January 28.59. The comet was recovered by Shin-ichi Shimizu (Simada, Japan) with an 80-mm astrograph on 1937 January 31.43. The comet was found after an assiduous search around the positions predicted by Hirose. Shimizu said it appeared as a 13th-magnitude diffuse object, without a nucleus. Confirming photographic observations were obtained by Shimizu on February 2.43 and February 3.43, with the magnitude being estimated as 12.5. Hirose's prediction needed a correction of only -0.710 day. The comet had just passed perihelion and was two months passed its closest approach to Earth. It steadily faded during the remainder of the apparition, reaching magnitude 14.5 at the beginning of March and 16 around mid-March. It was last seen on April 1, by L. Volta (Pino Torinese Observatory, Turin, Italy).
  • Close approaches to planets: The comet experienced three close approaches to Earth and four close approaches to Jupiter during the 20th century. It makes a minor approach to Jupiter early in the 21st century. (From the orbital work of Kazuo Kinoshita)
    • 0.42 AU from Earth on 1909 December 7 (contributed to comet's discovery)
    • 0.65 AU from Jupiter on 1912 February 5
      • increased perihelion distance from 1.38 AU to 1.53 AU
      • increased orbital period from 6.48 to 6.80 years
      • contributed to comet being lost for three apparitions
    • 0.88 AU from Earth on 1936 November 12
    • 0.60 AU from Earth on 1943 December 13
    • 1.38 AU from Jupiter on 1948 September 9
      • decreased perihelion distance from 1.53 AU to 1.46 AU
      • decreased orbital period from 6.80 to 6.66 years
    • 0.53 AU from Jupiter on 1959 July 23
      • increased perihelion distance from 1.46 AU to 1.66 AU
      • increased orbital period from 6.66 to 7.09 years
    • 0.25 AU from Jupiter on 1995 February 16
      • increased perihelion distance from 1.65 AU to 2.16 AU
      • increased orbital period from 7.06 to 8.07 years
    • 1.39 AU from Jupiter on 2018 December 2
      • increases perihelion distance from 2.16 AU to 2.24 AU
      • increases orbital period from 8.07 to 8.29 years