Discovered by K. Reinmuth MPC designation 1404 Ajax Named after Ajax (Greek mythology) Discovered 17 August 1936 Orbits Sun Asteroid group Jupiter trojan | Discovery date 17 August 1936 Pronunciation ˈeɪdʒæks (ay'-jaks) Alternative names 1936 QW Inclination 18.003° Discoverer Karl Wilhelm Reinmuth | |
Discovery site Landessternwarte Heidelberg-Königstuhl Similar 911 Agamemnon, 588 Achilles, Jupiter trojan, 617 Patroclus, Sun | ||
1404 Ajax (AY-jaks), provisional designation 1936 QW, is a carbonaceous Jupiter trojan from the Greek camp, approximately 82 kilometers in diameter. It was discovered on 17 August 1936, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany.
Ajax is a C-type asteroid, that orbits 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 4.7–5.9 AU once every 12 years and 3 months (4,461 days). Its orbit has an eccentricity of 0.11 and an inclination of 18° with respect to the ecliptic. The body's observation arc begins at Heidelberg 6 days after its official discovery observations, with no precoveries taken, and no prior identifications made.
In December 2010, a rotational light-curve of Ajax was obtained from photometric observations taken at the Chilean CTIO and at the Goat Mountain Astronomical Research Station (G79). Light-curve analysis gave a rotation period of 29.38 hours with a brightness variation of 0.30 magnitude (U=3-). Previous observations by Richard P. Binzel in 1988, and by Roberto Crippa and Federico Manzini in 2009, gave a period of 28.4 and 34 hours, respectively (U=1/2-).
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ajax measures between 81.69 and 96.34 kilometers in diameter, and its surface has an albedo between 0.048 and 0.067. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0508 and a diameter of 81.43 kilometers using an absolute magnitude of 9.3.
Jupiter trojans are thought to have been captured into their orbits during or shortly after the early stages of the formation of the Solar System. More than 4,000 Jupiter trojans in the Greek camp have already been discovered.
This minor planet is named for Ajax the Great, a Greek warrior of great strength and courage in the Trojan War. He is the half brother of Teucer and son of king Telamon, who kills himself because Achilles' armor was awarded to Odysseus. The Jupiter trojans 588 Achilles, 1143 Odysseus and 1749 Telamon and 2797 Teucer are all named after these figures from Greek mythology. Naming of Ajax was first cited in The Names of the Minor Planets by Paul Herget in 1955 (H 127).