Copyright © 2009 by Gary W. Kronk (Kronk Observatory, Illinois, USA)
This image was obtained by G. W. Kronk on 2009 January 14.02, using a 20-cm Meade LX200 and a MallinCam Hyper Black and White video camera. A total of 34 15-second exposures were stacked in Registax. The inset is to the same scale as the main image, but is processed to show isophotes (lines of constant light intensity), which reveal the coma is elongated toward the northeast.
Yoshio Kushida (Yatsugatake South Base Observatory, Japan) discovered this comet on Technical Pan 6415 patrol film shot with a 0.10-m f/4.0 telescope on 1994 January 8.81. He estimated the magnitude as 13.5. The comet was near the edge of the photograph and exhibited a strong central condensation within a coma 1-2 arc minutes across.
The first orbit released for this comet was a parabolic one computed by S. Nakano and published on IAU Circular 5919 (1994 January 11). Based on 25 positions gathered during the period of 1994 January 9 to 11, he determined the perihelion date as 1993 December 5.33 and the perihelion distance as 1.36 AU. The low inclination prompted Nakano to suggest the comet "may be a short-period comet." On January 14 Daniel W. E. Green confirmed Nakano's suggestion and published a short-period orbit on IAU Circular 5922. Based on 29 positions obtained during the period of January 9-13, Green determined a perihelion date of 1993 December 12.99, a perihelion distance of 1.37 AU, and an orbital period of 7.20 years.
Although most CCD imaging acquired by various observers in the days following the discovery indicated the comet's total magnitude was between 12.5 and 13, R. Keen (Colorado, USA) was the first visual observer to see the comet. He reported that his 0.32-m reflector revealed the comet at magnitude 10.7 on January 11, with a coma about 2.5 arc minutes across. Within the next few days other observers indicated the comet was much brighter than 12, with most giving a magnitude of 11 or brighter. Although the orbit indicated the comet should have been fading following the discovery as it moved away from both the sun and Earth, observers reported little difference in the brightness through the remainder of January and throughout February. As March began magnitude estimates were still in the range of 11 to 12, but they dropped to 13 by month's end. The comet continued to be followed as it faded and was last seen on July 9.18, when J. V. Scotti (Spacewatch, Arizona, USA) determined the total magnitude as 19.4, while the magnitude of the nuclear condensation was given as 22.7.
Following the final observations of this comet, Patrick Rocher determined an orbit. Rocher used 325 positions obtained between 1994 January 7 and July 9 and determined the perihelion date as 1993 December 12.862, the perihelion distance as 1.367 AU, and the orbital period as 7.366 years. He estimated the period's uncertainty as ±0.2324 day.
The comet's next perihelion date was 2001 June 27 and it was recovered by C. E. Delahodde and O. R. Hainaut (European Southern Observatory, La Silla) on 2000 July 25. Their observation on July 27 was also the last obtained during this apparition.
The comet's third apparition was expected to be nearly as good as the first, with the perihelion passage coming on 2009 January 26.86. Although the recovery announcement was made on 2008 July 8, it referred to observations made during June and July of 2007! The comet was officially recovered by Karen Meech and Jana Pittichova (Mauna Kea, Hawaii, USA) using the 10-meter Keck II reflector on 2007 June 18. Three images were obtained in the course of 54 minutes. The purpose of these images was to help the Spitzer Space Telescope observe this comet, which it did on 2007 July 9 and 10. The next observation of this comet did not come until 2008 September 9, when W. Hasubick obtained an image of the comet using his 44-cm reflector and a CCD camera. He gave the total magnitude as 20.4. Numerous observations by other observers were obtained during the weeks that followed.
Copyright © 1994 by Herman Mikuz (Crni Vhr Observatory, Slovenia)
This false-color image was obtained by H. Mikuz on 1994 January 23.16, using a 0.20-m f/2 Baker-Schmidt telescope, a V filter, and an ST-6 CCD. The comet is the large diffuse object. The exposure time was 5 minutes.