6545 Leitus, provisional designation: 1986 TR₆, is a Jupiter trojan from the Greek camp, approximately 53 kilometers (33 miles) in diameter. It was discovered on 5 October 1986, by Slovak astronomer Milan Antal at the Piwnice Astronomical Observatory in Poland.^[1] The dark D-type asteroid has a rotation period of 16.3 hours and belongs to the 90 largest Jupiter trojans.^[9] Numbered in 1995, it was named in 2021, after the Argonaut Leitus from Greek mythology, who fought in the Trojan War.^[13]

Leitus is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's L₄ Lagrangian point, 60° ahead of the Gas Giant's orbit in a 1:1 resonance (see Trojans in astronomy).^[4] It is also a non-family asteroid in the Jovian background population.^[5] It orbits the Sun at a distance of 4.9–5.4 AU once every 11 years and 8 months (4,265 days; semi-major axis of 5.15 AU). Its orbit has an eccentricity of 0.05 and an inclination of 12° with respect to the ecliptic.^[3] The body's observation arc begins with its official discovery observation at Piwnice in October 1986.^[1]

This minor planet was numbered on 9 September 1995 (M.P.C. 25628).^[13] On 29 November 2021, IAU's Working Group for Small Bodies Nomenclature named it after the Argonaut Leitus from Greek mythology. He was one of the seven Achaean Leaders in front of whom Poseidon appeared during the Trojans' attack on the Achaean ships, urging them to fight back instead of acting like cowards. Wounded by Hector, Leitus was one of the few to safely return home after the Trojan War.^[1][2]

In the SDSS-based taxonomy, Leitus is dark D-type asteroid,^[7][11] which agrees with the determined spectral type by Pan-STARRS.^[9][10] Its V–I color index of 0.91 is typical for most larger Jupiter trojans (also see table below).^[9]