120P/Mueller
120P/Mueller, also known as Mueller 1, is a Jupiter-family comet with an 8.4-year orbit around the Sun. It is one of 15 comets discovered by American astronomer, Jean Mueller.
Observational history
Jean Mueller first spotted the comet on photographic plates exposed from the Palomar Observatory on the night of 18 October 1987. She described the new comet as a diffuse 17th-magnitude object within the constellation Pisces. A condensation and an apparent tail about 20–30 arcseconds in length towards the south-southwest was also noted. Orbital calculations using follow-up observations until 27 October 1987 helped Daniel W. E. Green to determine Mueller's comet as periodic, at the time having an orbital period of roughly 8.21 years.James V. Scotti recovered the comet from the Kitt Peak Observatory on 30 July 1995 as P/1995 O1. It was a 22nd-magnitude object at the time of its recovery. The comet was observed from every subsequent apparition since. It most recently came to perihelion in May 2021 and underwent a 1.4 magnitude outburst in August 2021.