7958 Leakey
{{Use dmy dates|date=October 2019}}
{{Infobox planet
| minorplanet = yes
| name = 7958 Leakey
| background = #D6D6D6
| image =
| image_size =
| caption =
| discovered = 5 June 1994
| discoverer = C. S. Shoemaker
E. M. Shoemaker
| discovery_site = Palomar Obs.
| mpc_name = (7958) Leakey
| alt_names = {{mp|1994 LE|3}}{{·}}1991 GT
| named_after = Leakey family
{{small|(Mary, Louis, Richard)}}
| mp_category = {{nowrap|main-belt{{·}}Hungaria }}
| epoch = 4 September 2017 (JD 2458000.5)
| uncertainty = 0
| observation_arc = 31.09 yr (11,355 days)
| aphelion = 2.0211 AU
| perihelion = 1.7329 AU
| semimajor = 1.8770 AU
| eccentricity = 0.0768
| period = 2.57 yr (939 days)
| mean_anomaly = 296.31°
| inclination = 21.973°
| asc_node = 195.74°
| arg_peri = 154.20°
| satellites = 1 {{efn|name=Warner}}{{efn|name=Stephens}}
| dimensions = {{val|2.94|0.17}} km
3.35 km {{small|(calculated)}}
| rotation = {{val|2.34831|0.00003}} h{{efn|name=Stephens}}
{{val|2.34843|0.00006}} h{{efn|name=Warner}}
| albedo = 0.30 {{small|(assumed)}}
{{val|0.468|0.073}}
| spectral_type = E
}}
7958 Leakey, provisional designation {{mp|1994 LE|3}}, is a Hungaria asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 3 kilometers in diameter.
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.
Physical characteristics
Leakey is an assumed E-type asteroid.
= Lightcurves =
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 ({{small|U=3/3/3-}}).{{efn|name=Warner}}{{efn|name=Stephens}}{{efn|name=Coley}}
= Diameter and albedo =
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Leakey measures 2.94 kilometers in diameter and its surface has a high albedo of 0.468.
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.
= Moon =
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.{{efn|name=Warner}}
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 ({{small|716}}), it is tentatively estimated that the size-ratio of the binary system is {{val|0.3|0.03}}, which would give a 1-kilometer diameter for the satellite.
Naming
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 ({{small|M.P.C. 31612}}).
Notes
{{notelist|refs=
{{efn|name=Stephens|1=Stephens (2015): [http://www.planetarysciences.org/plots/RDS/7958_LEAKEY_2015-10-04.PNG lightcurve plot] of (7958) Leakey with rotation period {{val|2.34831|0.00003}} hours and a brightness amplitude of {{val|0.19}} mag. Summary figures at [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=7958%7CLeakey Collaborative Asteroid Lightcurve Link (CALL)]}}
{{efn|name=Coley|1=Daniel Coley (2012): [http://www.planetarysciences.org/plots/DC/7958_LEAKEY_2012-06-16.PNG lightcurve plot] of (7958) Leakey, at the Center for Solar System Studies (CS3).}}
{{efn|name=Warner|1=Warner (2012): [http://www.minorplanetobserver.com/pdolc/A7958_2012.HTM Lightcurve plot] of 7958 Leakey and its minor-planet moon (second plot) at the Palmer Divide Observatory, B. D. Warner (2012)}}
}}
References
{{reflist|30em|refs=
|type = 2017-06-06 last obs.
|title = JPL Small-Body Database Browser: 7958 Leakey (1994 LE3)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007958
|publisher = Jet Propulsion Laboratory
|access-date = 4 July 2017}}
|title = Dictionary of Minor Planet Names – (7958) Leakey
|last = Schmadel | first = Lutz D.
|publisher = Springer Berlin Heidelberg
|page = 625
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_6763 |chapter = (7958) Leakey }}
|title = 7958 Leakey (1994 LE3)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=7958
|access-date = 4 December 2016}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|access-date = 4 December 2016}}
|last1 = Johnston|first1=Robert
|title = (7958) Leakey
|url = http://www.johnstonsarchive.net/astro/astmoons/am-07958.html
|website = johnstonsarchive.net
|access-date = 29 May 2015}}
|title = LCDB Data for (7958) Leakey
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=7958%7CLeakey
|access-date = 4 December 2016}}
|display-authors = 6
|first1 = Joseph R. |last1 = Masiero
|first2 = A. K. |last2 = Mainzer
|first3 = T. |last3 = Grav
|first4 = J. M. |last4 = Bauer
|first5 = R. M. |last5 = Cutri
|first6 = C. |last6 = Nugent
|first7 = M. S. |last7 = Cabrera
|date = November 2012
|title = Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M
|journal = The Astrophysical Journal Letters
|volume = 759
|issue = 1
|page = 5
|bibcode = 2012ApJ...759L...8M
|doi = 10.1088/2041-8205/759/1/L8
|arxiv = 1209.5794
|access-date= 4 December 2016}}
|author = Warner, Brian D.
|author2 = Coley, Daniel
|author3 = Harris, Alan W.
|date = October 2012
|title = Lightcurve for 7958 Leakey: A New Hungaria Binary
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012MPBu...39..240W
|journal = The Minor Planet Bulletin
|volume = 39
|issue = 4
|pages = 240–241
|issn = 1052-8091
|bibcode = 2012MPBu...39..240W
|access-date= 17 December 2015}}
}}
External links
- [http://www.johnstonsarchive.net/astro/asteroidmoons.html Asteroids with Satellites], Robert Johnston, johnstonsarchive.net
- [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }})
- [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books
- [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend
- [https://minorplanetcenter.net/iau/lists/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center
- {{AstDys|7958}}
- {{JPL small body}}
{{Minor planets navigator |7957 Antonella |number=7958 |7959 Alysecherri}}
{{Small Solar System bodies}}
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Category:Discoveries by Carolyn S. Shoemaker