121P/Shoemaker–Holt, also known as Shoemaker–Holt 2, is a Jupiter-family comet with an orbital period of about 10 years. The comet was discovered by Carolyn S. Shoemaker, Eugene M. Shoemaker, and Henry E. Holt on 9 March 1989. The comet then had an apparent magnitude of 13, was diffuse and had a tail about 2 arcminutes long. It was recovered by James V. Scotti on 29 August 1995 in images obtained as part of the Spacewatch survey. The nucleus of the comet is estimated to have a radius of 3.87 km based on infrared imaging by the Spitzer Space Telescope, when the comet displayed dust emission. Observations of the comet from the Isaac Newton Telescope indicate an effective radius of 3.61 kilometers. The rotational period was calculated to be 10 hours, but with high uncertainty.
References
External links 121P/Shoemaker–Holt at the JPL Small-Body Database 121P/Shoemaker–Holt at Gideon van Buitenen's website 121P/Shoemaker–Holt at Gary W. Kronk's Cometography 121P/Shoemaker–Holt at Shuichi Nakano's website 121P/Shoemaker–Holt at Seiichi Yoshida's website