24P/Schaumasse

24P/Schaumasse
Discovery
Discovered by	Alexandre Schaumasse
Discovery date	1 December 1911
Designations
Alternative designations	1911 X1, 1919 U1
Orbital characteristics
Epoch	2025-12-31
Aphelion	6.93 AU
Perihelion	1.183 AU
Semi-major axis	4.06 AU
Eccentricity	0.7083
Orbital period	8.18 yr
Inclination	11.50°
Last perihelion	16 November 2017; 9 August 2009; (unobserved)
Next perihelion	2026-Jan-08
Physical characteristics
Dimensions	2.6 km

Comet Schaumasse is a periodic comet discovered by Alexandre Schaumasse (Nice, France) on 1 December 1911 as 12th magnitude.^[5] It next comes to perihelion on 8 January 2026 and should brighten to about magnitude 9.^[2]

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.^[5] The 1919 return was recovered by Gaston Fayet (Paris, France) as magnitude 10.5.^[5]

The 1927 approach was magnitude 12, but the comet was missed on the 1935 approach.^[5] In 1937 it passed close to Jupiter which increased its orbital period slightly.^[5] During the 1951-1952 apparition, the comet was brighter than expected, reaching a magnitude of about 6 in February.^[5]

The comet was missed in 1968 and 1976.^[5] 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).^[6] Also in 1984 was reported that Elizabeth Roemer (Steward Observatory, Arizona, USA) had found a comet on a photograph from 27 December 1976.^[5] Orbital calculations by Brian G. Marsden, confirmed the 1976 image featured Comet Schaumasse.^[5]^[6]

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 0.025 AU (4 million km) of the dwarf planet Ceres on 22 March 2010.^[4] During the 2017 apparition the comet reached a magnitude of 10.^[7] It was last observed on 19 June 2018 when it was 2.7 AU from the Sun.^[1]

24P/Schaumasse closest Earth approach on 2026-Jan-04^[5]
Date & time of closest approach	Earth distance (AU)	Sun distance (AU)	Velocity wrt Earth (km/s)	Velocity wrt Sun (km/s)	Uncertainty region (3-sigma)	Reference
2026-Jan-04	0.597 AU (89.3 million km; 55.5 million mi; 232 LD)	1.19 AU (178 million km; 111 million mi; 460 LD)	19.0	35.8	± 420 thousand km	Horizons

Around 3 October 2100 it should pass about 0.27 AU (40 million km) from Mars.^[8]

The comet nucleus is estimated to be 2.6 kilometers in diameter.^[4]

References

^ ^a ^b ^c MPC
^ ^a ^b ^c Seiichi Yoshida (2009-04-07). "24P/Schaumasse". Seiichi Yoshida's Comet Catalog. Retrieved 2010-02-24.
^ Kinoshita, Kazuo (2018-04-07). "24P/Schaumasse past, present and future orbital elements". Comet Orbit. Archived from the original on 2011-07-10. Retrieved 2023-07-29.
^ ^a ^b ^c "JPL Small-Body Database Browser: 24P/Schaumasse" (last observation: 2018-06-19). Jet Propulsion Laboratory. Archived from the original on 2012-12-12. Retrieved 2010-02-25.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Kronk, Gary W. (2001–2005). "24P/Schaumasse". Archived from the original on 2011-09-23. Retrieved 2007-01-31.
^ ^a ^b Gibson, J.; Roemer, E.; Marsden, B. G. (1 September 1984). "Periodic Comet Schaumasse (1976 XV = 1984m)". International Astronomical Union Circular (3986): 2. ISSN 0081-0304.
^ Champo, Pepe (23 November 2017). "COMET 24P/SCHAUMASSE (NOV.19,2017)". Sky & Telescope. Retrieved 29 March 2023.
^ "Horizons Batch for 24P/Schaumasse (90000353) on 2100-Oct-03". JPL Horizons. Retrieved 2023-07-29. (JPL#K173/9 Soln.date: 2018-Sep-24)