It orbits the Sun at a distance of 5.1–5.2 AU once every 11 years and 8 months (4,263 days; semi-major axis of 5.15 AU). Its orbit has an eccentricity of 0.02 and an inclination of 7° with respect to the ecliptic.[4] The asteroid was first observed in a precovery taken at Lowell Observatory in March 1959. The body's observation arc begins with its official discovery observation at Nauchnij in August 1977.[1]
Naming
This minor planet is named after Antenor, one of the wisest of the elders and counselor of King Priam of Troy. Sympathetic to a negotiated peace with the Greeks, he advised his countrymen to return Helen of Troy to Menelaus during the Trojan War.[3](The minor planets 884 Priamus, 101 Helena and 1647 Menelaus are also named after these figures from Greek mythology.) In later accounts, Antenor was made an open traitor, who unsealed the gates of Troy to the Greek enemy. The official naming citation was published by the Minor Planet Center on 1 March 1981 (M.P.C. 5849).[20]
The first rotational lightcurves of Antenor were obtained from photometric observations in October 1989, by astronomers Mario Di Martino and Maria Gonano–Beurer with the now decommissioned ESO 1-metre telescope at La Silla in Chile.[15][16] In April 1969, a follow-up observation by Mottola gave the so-far best-rated rotation period of in 7.965 hours with a brightness variation of 0.09 magnitude (U=2+).[5][15]
In October 2018, Stephens, in collaboration with Brian Warner (716) and several other European observers including Amadeo Aznarand (Z95)/(J42) and Vladimir Benishek at Belgrade Observatory, reported that Antenor is likely a binary system. An orbital period for the suspected minor-planet moon could not be determined. If confirmed, it would be 5th known binary Jupiter trojan.[8]
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Antenor measures between 85.11 and 97.66 kilometers in diameter and its surface has an albedo between 0.051 and 0.0678.[9][10][11] The Collaborative Asteroid Lightcurve Link an albedo of 0.0678 and a diameter of 85.11 kilometers based on an absolute magnitude of 8.89.[5]
100+ largest Jupiter trojans
Largest Jupiter Trojans by survey(A) (mean-diameter in kilometers; YoD: Year of Discovery)
Note: missing data was completed with figures from the JPL SBDB (query) and from the LCDB (query form) for the WISE/NEOWISE and SIMPS catalogs, respectively. These figures are given in italics. Also, listing is incomplete above #100.
Notes
^ abcLightcurve plots of (2207) Antenor from Feb 2016, Apr 2017 and Jan 2018 by Robert Stephens at the Center for Solar System Studies (U81). Quality code is 3/3-/3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3.
^ abcdTedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 15 June 2018.
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)