# 954 Li **954 Li** (provisional designation 1921 JU) is a main-belt asteroid about 58 km across, discovered on 4 August 1921 by the German astronomer Karl Wilhelm Reinmuth at [Heidelberg](https://www.edgepedia.org/heidelberg) and named for his wife, Lina Alstede Reinmuth.[1](https://astronomia.zcu.cz/planety/planetka-954) • [2](https://ndl.ethernet.edu.et/bitstream/123456789/32939/1/Lutz%20D.%20Schmadel.pdf) | Key fact | Detail | |---|---| | Discovery | 4 August 1921 by K. Reinmuth at Heidelberg; provisional designation 1921 JU[1](https://astronomia.zcu.cz/planety/planetka-954) | | Name origin | Honors Mrs. Lina Alstede Reinmuth, the discoverer's wife; asteroid (955) Alstede honors her as well[2](https://ndl.ethernet.edu.et/bitstream/123456789/32939/1/Lutz%20D.%20Schmadel.pdf) | | Orbit | Semi-major axis 3.1286 au, eccentricity 0.1737, inclination 1.1727°, orbital period 5.534 years[1](https://astronomia.zcu.cz/planety/planetka-954) | | Distance range | Perihelion 2.585 au, aphelion 3.672 au[1](https://astronomia.zcu.cz/planety/planetka-954) | | Size and brightness | Diameter about 58 km; absolute magnitude H = 10.15 with slope parameter G = 0.15[3](https://occultations.org.nz/planet/2006/updates/061229_954_11373_u.htm) • [4](https://in-the-sky.org/data/object.php?id=A954) | | Observation record | 6,393 observations over 57 oppositions, spanning 1905 to 2026[1](https://astronomia.zcu.cz/planety/planetka-954) | ## Discovery and naming Reinmuth found 954 Li at the Heidelberg Observatory on 4 August 1921, and the [Minor Planet Center](https://www.edgepedia.org/minor-planet-center) later cataloged it under the number 954.[1](https://astronomia.zcu.cz/planety/planetka-954) According to the *Dictionary of Minor Planet Names*, the name honors Mrs. Lina Alstede Reinmuth, the discoverer's wife, and Reinmuth honored her a second time: asteroid (955) Alstede, which he discovered the following day, 5 August 1921, carries her middle name.[2](https://ndl.ethernet.edu.et/bitstream/123456789/32939/1/Lutz%20D.%20Schmadel.pdf) The object's observation history reaches back before its discovery. The Czech asteroid database records 6,393 observations across 57 oppositions, with the observation record covering 1905 through 2026 and the most recent observation dated 24 May 2026.[1](https://astronomia.zcu.cz/planety/planetka-954) ## Orbit 954 Li is an outer main-belt object. Its orbit has a semi-major axis of 3.1286 au, an eccentricity of 0.1737, and an inclination of only 1.1727° to the ecliptic, so it travels between 2.585 au at perihelion and 3.672 au at aphelion, completing one revolution in 5.534 years (2,021.2 days).[1](https://astronomia.zcu.cz/planety/planetka-954) Its Jupiter Tisserand parameter, a value used to distinguish asteroidal from cometary orbits, is 3.2.[1](https://astronomia.zcu.cz/planety/planetka-954) Because the orbit lies entirely beyond 2.5 au, the asteroid never comes close to Earth. The closest approach computed in the Czech database is 1.57 au on 1 August 2032, when the asteroid also reaches its brightest apparent magnitude from Earth, 13.3 mag on 31 July 2032; at its farthest, 4.68 au on 11 August 2046, it fades to 16.9 mag.[1](https://astronomia.zcu.cz/planety/planetka-954) ## Physical properties **Size and albedo.** A diameter of about 58 km follows from the asteroid's brightness and low albedo. The German-language summary gives a mean diameter of 58.02 km with an albedo of 0.056, and the RASNZ occultation predictions for the 2006 event used an approximate diameter of 58 km.[3](https://occultations.org.nz/planet/2006/updates/061229_954_11373_u.htm) A 2020 occultation prediction used a slightly smaller value of 53 km.[5](https://occultations.org.nz/planet/2020/updates/200415_954_64706_u.htm) The absolute magnitude is H = 10.15 with a slope parameter G = 0.15.[4](https://in-the-sky.org/data/object.php?id=A954) **Rotation.** The rotation period is not settled to a single value. The Minor Planet Bulletin's lightcurve listing gives a period of 7.207 hours with an amplitude of 0.11 to 0.25 mag and a quality code of 3.[6](https://mpbulletin.org/issues/MPB_47-2.pdf) A reconstruction of spin states from Gaia DR3 photometry derived a period of 14.4099 hours for 954 Li and notes that a period around 14 hours had also been reported at Raoul Behrend's CdR&CdL web page, which is consistent with the 7.207-hour value being half of the true period.[7](https://www.researchgate.net/publication/370869441_Reconstruction_of_asteroid_spin_states_from_Gaia_DR3_photometry) The DAMIT database (Database of Asteroid Models from Inversion Techniques) holds a light curve entry for the asteroid but lists no shape model for it.[8](https://damit.cuni.cz/asteroids/view/10685) ## Occultations Because 954 Li is large and its orbit is well known, it produces useful stellar occultations. On 29 December 2006 UT it occulted an 11.2-magnitude star (TYC 1342-00894-1) in the constellation Gemini along a path across the South Island of New Zealand, including [Christchurch](https://www.edgepedia.org/christchurch); the prediction was based on 931 used observations spanning 26 October 1905 to 12 December 2006, with a 1-sigma uncertainty ellipse of 0.027 by 0.022 arcseconds.[3](https://occultations.org.nz/planet/2006/updates/061229_954_11373_u.htm) A second event was predicted for 15 April 2020 UT, when the asteroid would occult a 12.5-magnitude star in Virgo along a path crossing New Zealand, New South Wales, northern [South Australia](https://www.edgepedia.org/south-australia), and central [Western Australia](https://www.edgepedia.org/western-australia).[5](https://occultations.org.nz/planet/2020/updates/200415_954_64706_u.htm) ## References 1. [Planetka Li (954), Planety – Czech asteroid database](https://astronomia.zcu.cz/planety/planetka-954) 2. [Lutz D. Schmadel, Dictionary of Minor Planet Names, 5th edition (entry for (954) Li)](https://ndl.ethernet.edu.et/bitstream/123456789/32939/1/Lutz%20D.%20Schmadel.pdf) 3. [RASNZ Occultation Section – Occultation by (954) Li, 2006 Dec 29](https://occultations.org.nz/planet/2006/updates/061229_954_11373_u.htm) 4. [954 Li (Asteroid), In-The-Sky.org](https://in-the-sky.org/data/object.php?id=A954) 5. [RASNZ Occultation Section – Occultation by (954) Li, 2020 Apr 15](https://occultations.org.nz/planet/2020/updates/200415_954_64706_u.htm) 6. [Minor Planet Bulletin 47-2, lightcurve parameter listing](https://mpbulletin.org/issues/MPB_47-2.pdf) 7. [Reconstruction of asteroid spin states from Gaia DR3 photometry](https://www.researchgate.net/publication/370869441_Reconstruction_of_asteroid_spin_states_from_Gaia_DR3_photometry) 8. [Asteroid (954) Li, DAMIT database](https://damit.cuni.cz/asteroids/view/10685) --- *Topic: Encyclopedia › Places and geography › Extraterrestrial places › Small bodies of the Solar System › Main-belt asteroids and numbered minor planets › Outer-belt asteroids › Themis-region asteroids* *Initially written Oct 21, 2026 · Edited: Oct 25, 2026* *Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.* License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license