4060 Deipylos

Deipylos is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's L₄ Lagrangian point, 60° ahead its orbit in a 1:1 resonance (see Trojans in astronomy). It is a non-family asteroid in the Jovian background population.^[6][14] It orbits the Sun at a distance of 4.4–6.1 AU once every 12.03 years (4,392 days; semi-major axis of 5.25 AU). Its orbit has an eccentricity of 0.15 and an inclination of 16° with respect to the ecliptic.^[3]

The body's observation arc begins with its first observation as 1942 ET at Turku Observatory in March 1942yxz years prior to its official discovery observation.^[1]

Deipylos has been characterized as a carbonaceous C-type asteroid in the Tholen-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2). In their SMASS-like taxonomy, S3OS2 classified Deipylos as an Cb-subtype that transitions to the somewhat brighter B-type asteroids.^[14][15] The Collaborative Asteroid Lightcurve Link also assumes it to be of carbonaceous composition.^[4]

In December 2010, a rotational lightcurve of Deipylos was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 11.490 hours with a brightness amplitude of 0.11 magnitude (U=2)^[13] Between 2015 and 2017, several observations by Robert Stephens in collaboration with Daniel Coley and Brian Warner at the Center for Solar System Studies (U81) in California gave a more refined period between 9.19 and 9.38 hours and an amplitude of 0.07–0.13 magnitude (U=3-/3-/3-/2+).^[10][11][12] The best-rated result gave 9.298 hours with an amplitude of 0.07±0.02 magnitude.^[4][11][a]

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, Deipylos measures between 79.21 and 86.79 kilometers in diameter and its surface has an albedo between 0.043 and 0.078.^[7][8][9] CALL assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 66.34 kilometers based on an absolute magnitude of 9.62.^[4]

This minor planet was named after Deipylos a Greek hero in the Trojan War. He was a fellow of Sthenelus (Sthenelos), who ordered him to bring the horses captured from Aeneas to the Greek vessels.^[1] The official naming citation was published by the Minor Planet Center on 15 September 1989 (M.P.C. 15090).^[17]