Copyright © 2007 by L. Donato, E. Guido, and G. Sostero (Remanzacco Observatory, Italy)
These are two of the first four recovery images obtained of this comet during the 2007 apparition. These CCD images was taken on 2007 July 21 and 22, using a 45-cm Newtonian reflector and a CCD camera.
Jean Mueller (Palomar Observatory, California, USA) discovered this comet on photographic plates exposed on 1990 September 24 and 25 with the 1.2-m Oschin Schmidt telescope in the course of the second Palomar Sky Survey. She estimated the magnitude as 18 and noted a faint tail extending westward.
Within a couple of days of the announcement, E. Bowell (Lowell Observatory, Arizona, USA) announced that prediscovery images had been found on plates exposed on September 17 and 19 by H. E. Holt, H. R. Holt, C. M. Olmstead, and J. A. Brown with the 0.46-m Schmidt telescope at Palomar Observatory. The comet appeared at magnitude 17.5 on those images.
Following the finding of the prediscovery positions, Bowell computed an orbit which was first published on September 28. The orbit indicated the comet was moving in a short-period orbit with a period of 8.56 years. Further revisions using a larger number of observations proved Bowell's initial orbit was not far off, as the orbital period proved to be 8.65 years.
The comet did not become brighter, but held steady at about magnitude 17.5 until mid-October. Thereafter, fading became more rapid as the comet's distances from the sun and Earth increased. The comet was last seen on December 15 by observers at Oak Ridge Observatory.
Apparition of 1999: The comet was recovered by James V. Scotti (Lunar and Planetary Laboratory)
on 1998 May 24 with the 0.91-m Spacewatch telescope on Kitt Peak. The CCD images indicated a nuclear magnitude between 20.6 and 21.4. On May 26 Scotti said the comet was very slightly diffuse, with a coma diameter of 12 arc seconds. Precise positions indicated the prediction by S. Nakano required a correction of -0.7 day. The comet was last detected on 1999 December 26.56 by astronomers at the YGCO Chiyoda Station (Japan).
Apparition of 2007: The comet was recovered by L. Donato, E. Guido, and G. Sostero (Remanzacco Observatory, Italy) on images obtained on 2007 July 21.06, 21.07, and 21.08, as well as on July 22.04. They were using a 45-cm Newtonian reflector and a CCD camera. The images revealed a coma about 20" across and a broad tail nearly 15" long toward the southwest. The total magnitude was about 18.3, while the nuclear magnitude was about 18.9. An independent recovery was made by F. Fratev (Zvezdno Obshtestvo Observatory, Plana, Bulgaria) on images obtained on July 22.04, 22.05, and 22.06 that were obtained using a 25-cm reflector and a CCD camera. They gave the nuclear magnitude as about 18.9.