149P/Mueller 4

Past, Present, and Future Orbits by Kazuo Kinoshita

Copyright © 1993-2000 by the California Institute of Technology This image was obtained with the 48-inch Oschin Schmidt Telescope at Palomar Observatory (California, USA) on 1992 April 27.31. The comet trailed during the exposure of the Kodak IIIaF (red) plate, but still shows a trace of tail toward the lower right. This image was obtained through SkyMorph at the Goddard Space Flight Center. Discovery      A 90-minute IIIa-J exposure was obtained by Jean Mueller and C. Brewer (Palomar Observatory, California, USA) with the 1.2-m Oschin Schmidt telescope on 1992 April 9.35. Upon examining the plate a couple of days later, Mueller found the faint trail of a possible comet. She estimated the magnitude as 17.5 and noted a "possible hint of a tail to the west." She noted a 30-minute exposure was obtained of the same region with the same telescope on April 11.40 and she was able to locate a trail that was too weak to confirm whether it was a comet or a minor planet.      R. H. McNaught (Siding Spring Observatory, Australia) photographed the object with the Uppsala Schmidt telescope on April 12 and confirmed the cometary nature. He estimated the magnitude as 17. T. Seki (Geisei, Japan) also detected the comet on April 14 and noted a magnitude of 17. Historical Highlights The first orbit was calculated by B. G. Marsden (Central Bureau for Astronomical Telegrams). Using positions spanning the period of April 9-14, he found the comet was moving in a short-period orbit, with a perihelion date of 1992 January 27.56 and a period of 9.26 years. Ultimately the perihelion date proved to be February 16.11, while the period was 8.97 years. As the comet was moving away from both the sun and Earth, it slowly faded. Seki gave the magnitude as 17.5 on April 20 and 18.0 on April 22. The comet was last detected on July 2.10 by astronomers at Oak Ridge Observatory. The comet was recovered by T. Oribe (Saji Observatory) on 2000 December 22.85 with the 1.03-m reflector. The CCD images revealed the comet was faint and stellar, with a nuclear magnitude of 20.5. Oribe obtained further CCD images on 2001 January 30.83, which indicated a magnitude of 19.6. Seki also announced that he had detected the comet on January 27.78. The comet was followed until 2001 June 28.88, when it was detected by Pepe Manteca (Observatorio de Begues, Spain) using a 30-cm f/6.3 Schmidt-Cassegrain and a CCD camera. He gave the magnitude as 18.0. The comet is next expected to return to perihelion on 2010 February 19.20. Additional Images Copyright © 2001 by Akimasa Nakamura (Kuma Kogen Astronomical Observatory, Japan) This image was obtained by A. Nakamura on 2001 March 21.75 UT with a 60-cm f/6 reflector and a CCD camera. Copyright © 2001 by Pepe Manteca (Observatorio de Begues, Spain) This image was obtained by P. Manteca on 2001 May 29.97 UT with a Meade 30-cm LX200 and an SBIG ST9E CCD camera. It is a 300-second exposure. cometography.com