Comet Boattini 5, also known as 398P/Boattini, is a Jupiter-family comet with a 5.53-year orbit around the Sun. It is the 10th comet discovered by Italian astronomer, Andrea Boattini.
Observational history Boattini spotted this comet, initially designated as P/2009 Q4, as a 19th-magnitude object with a strongly condensed coma on the night of 26 August 2009. At the time, it was located in the constellation Taurus. Precovery images of the comet as early as January 2004 were also found. Additional astrometric measurements conducted in October 2009 had shown the comet as periodic, completing one revolution once every 5.5 years.
The comet was predicted to return in June 2015, but no observations were reported. However in August 2025, the COIAS project did found archival images of the comet's 2015 apparition, which was taken by the Subaru Telescope.
It was later recovered on its next apparition as P/2020 P2, on CCD images taken from the ATLAS facility of the Mauna Loa Observatory. It experienced an outburst on 28 September 2020 when it temporarily brightened by 1.4 magnitudes for four days. Observations from TESS noted that the comet exhibited a two-phase brightening on another outburst event in early 2021.
It was given a permanent numerical designation as 398P/Boattini in December 2020.
Physical characteristics Infrared observations conducted by the Wide-field Infrared Survey Explorer (WISE) in 2010 revealed that the nucleus of 398P/Boattini has an effective radius of around .
Narrowband-filter observations at the TRAPPIST-North facility of the Oukaïmeden Observatory in November 2020 detected emissions of cyanogen (CN) compounds in its coma, however it was noticeably depleted in carbon compounds ( and ), one of a few such carbon-chain poor Jupiter-family comets ever known.
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References
External links
at the Minor Planet Center database 398P/Boattini at Gideon van Buitenen's website 398P/Boattini at Seiichi Yoshida's website 398P/Boattini at TheSkyLive.com