Discovered by C. S. Shoemaker MPC designation 4348 Poulydamas Absolute magnitude 9.2 Discoverer Carolyn S. Shoemaker Asteroid group Jupiter trojan | Discovery date 11 September 1988 Discovered 11 September 1988 Orbits Sun Discovery site Palomar Observatory | |
Pronunciation pɒˈlɪdəməs (po-lid'-ə-məs) Named after Poulydamas
(Greek mythology) Alternative names 1988 RU · 1977 SP1
1977 TV4 · 1983 GJ
1988 PK4 Similar Jupiter trojan, Solar System, Sun, 617 Patroclus, 588 Achilles | ||
4348 Poulydamas (PO-lid'-Ə-məs), provisional designation 1988 RU, is a large carbonaceous Jupiter Trojan from the Trojan camp, approximately 80 kilometers in diameter. It was discovered by American astronomer Carolyn Shoemaker at the U.S. Palomar Observatory in California, on 11 September 1988.
The dark C-type asteroid orbits the Sun in the Trojan camp at a distance of 4.7–5.8 AU once every 12 years (4,382 days). Its orbit has an eccentricity of 0.10 and an inclination of 8° with respect to the plane of the ecliptic.
In December 1990, astronomers Stefano Mottola and Mario Di Martino used photometric observations made with the 1.52-meter Loiano Telescope at the Observatory of Bologna, Italy, to build a light-curve for this asteroid. It gave a rotation period of 7000990800000000000♠9.908±0.018 hours with a brightness variation of 6999210000000000000♠0.21±0.01 magnitude (U=3). In October 2013, observations at the Palomar Transient Factory gave a period of 9.9214 hours with an amplitude of 0.23 magnitude (U=2). In January 2015 and 2016, astronomer Robert D. Stephens at the Center for Solar System Studies (CS3) obtained two rotational light-curves that gave a period of 7000988000000000000♠9.88±0.01 and 7000994100000000000♠9.941±0.006 hours with a brightness variation of 0.19 and 0.27, respectively (U=3-/3-).
Based on the surveys carried out by the Japanese Akari and the NEOWISE mission of the U.S. Wide-field Infrared Survey Explorer, the asteroid has a very low albedo of 0.048 and 0.033, while the Collaborative Asteroid Lightcurve Link (CALL) assumes a somewhat higher albedo of 0.057 for the carbonaceous body. Accordingly, CALL calculates the asteroid's diameter to be only 67 kilometers while the two space-based surveys gave a larger diameter of 82 and 88 kilometers, respectively.
The minor planet was named after Poulydamas from Greek mythology, the closest counsellor and strategist of the Trojan prince Hector, after whom the minor planet 624 Hektor is named. Hector and Poulydamas were born on the same night. While the gods gave Hector the ability to perfectly master his arms, Poulydamas was given the present of better judgment. It was Poulydamas who urged to lock the gates of Troy against Achilles (also see 588 Achilles), but Hector left the city and confronted Achilles nonetheless, which led to his doom and to the eventual downfall of Troy. Naming citation was published on 28 April 1991 (M.P.C. 18141).