Comet Schaumasse is a Jupiter-family comet roughly 2 km in diameter with an 8.2-year orbit around the Sun. It is the first of three comets discovered by French astronomer, Alexandre Schaumasse. It last came to perihelion on 8 January 2026 and will next return on 16 March 2034.
Observations By the end of 1912 it was recognised as a short period comet estimated to return in 7.1 years, later recalculated as 8 years. The 1919 return was recovered by Gaston Fayet (Paris, France) as magnitude 10.5.
The 1927 approach was magnitude 12, but the comet was missed on the 1935 approach. In 1937, it passed close to Jupiter which increased its orbital period slightly. The comet reached magnitude 15 on its 1943-1944 apparition. During the 1951-1952 apparition, the comet was brighter than expected, reaching a magnitude of about 6 in February.
The comet was missed in 1968 and 1976. It was speculated that the increase in brightness in 1952 indicated a problem that led to it vanishing. The comet during the 1984 apparition was recovered by James B. Gibson (Palomar Observatory, California, USA). Also in 1984 was reported that Elizabeth Roemer (Steward Observatory, Arizona, USA) had found a comet on a photograph from 27 December 1976. Orbital calculations by Brian G. Marsden, confirmed the 1976 image featured Comet Schaumasse.
The comet was not observed during the 2009 unfavorable apparition since the perihelion passage occurred when the comet was on the far side of the Sun. It passed within of the dwarf planet Ceres on 22 March 2010. During the 2017 apparition the comet reached a magnitude of 10.
On 25 October 2025, it passed about 1 degree from Jupiter. It came to perihelion on 8 January 2026 with a solar elongation of 94 degrees and brightened to about magnitude 9. Two small outbursts, which brightened the comet by 0.7 and 1.1 magnitudes respectively, were recorded on March and May 2026.
+24P/Schaumasse closest Earth approach on 2026-Jan-04 Date & time ofclosest approach Earth distance(AU) Sun distance(AU) Velocitywrt Earth(km/s) Velocitywrt Sun(km/s) Uncertaintyregion(3-sigma) Reference 2026-Jan-04 18.9 35.8 ± 100 km Horizons
Around 25 October 2100 it should pass about from Mars.
Physical characteristics Initial light-curve analysis in 1994 by James V. Scotti revealed that the nucleus of 24P/Schaumasse is estimated to be about in diameter. Mid-infrared spectra taken by Martha S. Hanner supported this measurement. Newer calculations in 2006, based on its nuclear magnitude (M2) and water production rate, revised this value to .
Spectroscopic analysis of the comet in 1992 detected emissions of CN, , and NH within its coma, where significant variations at the amount of within from the comet were reported.
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References
External links
at the Minor Planet Center database 24P/Schaumasse at Kazuo Kinoshita's website 24P/Schaumasse at Seiichi Yoshida's website 24P/Schaumasse at Gary W. Kronk's Cometography