Discovery date 11 October 1985 Alternative names 1985 TG3 Absolute magnitude 10.4 | MPC designation 5023 Agapenor Discovered 11 October 1985 Orbits Sun | |
Discovered by C. ShoemakerE. Shoemaker Discoverers Carolyn S. Shoemaker, Eugene Merle Shoemaker Similar Jupiter trojan, 911 Agamemnon, Sun, Solar System, 588 Achilles | ||
5023 Agapenor, provisional designation 1985 TG3, is an asteroid, classified as a Jupiter trojan from the Greek camp, between 25 and 50 kilometers in diameter. It was discovered by American astronomer couple Carolyn and Eugene Shoemaker at the U.S. Palomar Observatory, California, on 11 October 1985.
The asteroid is orbiting in the leading Greek camp at Jupiter's L4 Lagrangian point, 60° ahead of its orbit (see Trojans in astronomy). It orbits the Sun at a distance of 4.9–5.4 AU once every 11 years and 9 months (4,302 days). Its orbit has an eccentricity of 0.05 and an inclination of 12° with respect to the ecliptic. The first precovery was taken at the discovering observatory in September 1985, extending the asteroid's observation arc by 25 days prior to its discovery.
In September 2009, the body was observed by astronomer Stefano Mottola in a photometric survey of 80 Jupiter trojans, using the 1.2-meter reflector at Calar Alto Observatory in southeastern Spain. The obtained light-curve gave a rotation period of 7000540200000000000♠5.4020±0.0017 hours with a brightness variation of 6999120000000000000♠0.12±0.01 in magnitude (U=2+).
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 27.9 kilometers in diameter and its surface has an albedo of 0.17. The body has a X-type spectrum based on a large-scale survey performed by Pan-STARRS, while the Collaborative Asteroid Lightcurve Link (CALL) classifies it as a C-type asteroid assuning a carbonaceous standard albedo of 0.057. As a consequence, CALL calculates a significantly larger diameter of 46.3 kilometers.
The minor planet was named from Greek mythology after Agapenor. He was the leader of the Greek contingent of Arcadians in the Trojan War. The minor planet 1020 Arcadia is named after this able group of warriors. Agapenor was the commander of 60 ships lend to him by Agamemnon, the king of Mycenae and leader of the Greeks in the Trojan War. 911 Agamemnon, one of the largest Jupiter trojans known to exist, is named after the commander of the Greek forces. Naming citation was published on 12 July 1995 (M.P.C. 25443).