|Discovered by||C. S. Shoemaker|
E. M. Shoemaker
|Discovery site||Palomar Obs.|
|Discovery date||5 June 1994|
|MPC designation||(7958) Leakey|
(Mary, Louis, Richard)
|1994 LE3 · 1991 GT|
|main-belt · Hungaria |
|Orbital characteristics |
|Epoch 4 September 2017 (JD 2458000.5)|
|Uncertainty parameter 0|
|Observation arc||31.09 yr (11,355 days)|
|2.57 yr (939 days)|
|Known satellites||1 [a][b]|
3.35 km (calculated)
It was discovered on 5 June 1994, by American astronomer-couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California, United States. Its minor-planet moon was discovered in 2012. The asteroid was named after the members of the Leakey family: Mary, Louis and Richard.
Orbit and classification
Leakey is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner main-belt at a distance of 1.7–2.0 AU once every 2 years and 7 months (939 days). Its orbit has an eccentricity of 0.08 and an inclination of 22° with respect to the ecliptic.
In 2012, and 2015, several lightcurves of Leakey were obtained by astronomers Brian Warner, Robert Stephens and Daniel Coley. Lightcurve analysis gave a concurring and well-defined rotation period of 2.35 hours with a brightness variation between 0.19 and 0.22 magnitude (U=3/3/3-).[a][b][c]
Diameter and albedo
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between 0.4 and 0.2, corresponding to the Hungaria asteroids both as family and orbital group – and calculates a diameter of 3.35 kilometers based on an absolute magnitude of 14.3.
The 2012-photometric lightcurve observation also revealed, that Leakey is a synchronous binary asteroid with a minor-planet moon orbiting it every 50.24 hours.[a] The moon (secondary) was designated S/2012 (7958) 1.
It is likely that the secondary body is tidally locked, which means that its rotation is synchronous with its orbital period. Based on only two observations at the Palmer Divide Observatory (716), it is tentatively estimated that the size-ratio of the binary system is 0.3±0.03, which would give a 1-kilometer diameter for the satellite.
The minor planet is named after the Leakey's, a family of Kenyan paleoanthropologists: Mary Leakey (1913–1996), her husband Louis Leakey (1903–1972), and their son Richard Leakey (born 1944). Working for many years in Tanzania and Kenya, they conclusively proved that human evolution began in Africa rather than Asia. Richard explored the Koobi Fora archaeological site in Kenya, where many Hominin fossils have been found. The approved naming citation was published by the Minor Planet Center on 11 April 1998 (M.P.C. 31612).
- Warner (2012): Lightcurve plot of 7958 Leakey and its minor-planet moon (second plot) at the Palmer Divide Observatory, B. D. Warner (2012)
- Stephens (2015): lightcurve plot of (7958) Leakey with rotation period 2.34831±0.00003 hours and a brightness amplitude of 0.19 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)
- Daniel Coley (2012): lightcurve plot of (7958) Leakey, at the Center for Solar System Studies (CS3).
- "JPL Small-Body Database Browser: 7958 Leakey (1994 LE3)" (2017-06-06 last obs.). Jet Propulsion Laboratory. Retrieved 4 July 2017.
- Schmadel, Lutz D. (2007). "(7958) Leakey". Dictionary of Minor Planet Names – (7958) Leakey. Springer Berlin Heidelberg. p. 625. doi:10.1007/978-3-540-29925-7_6763. ISBN 978-3-540-00238-3.
- "7958 Leakey (1994 LE3)". Minor Planet Center. Retrieved 4 December 2016.
- "LCDB Data for (7958) Leakey". Asteroid Lightcurve Database (LCDB). Retrieved 4 December 2016.
- Johnston, Robert. "(7958) Leakey". johnstonsarchive.net. Retrieved 29 May 2015.
- Warner, Brian D.; Coley, Daniel; Harris, Alan W. (October 2012). "Lightcurve for 7958 Leakey: A New Hungaria Binary". The Minor Planet Bulletin. 39 (4): 240–241. Bibcode:2012MPBu...39..240W. ISSN 1052-8091. Retrieved 17 December 2015.
- Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 4 December 2016.
- "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 December 2016.
- Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
- 7958 Leakey at the JPL Small-Body Database