11395 Iphinous (provisional designation 1998 XN₇₇) is a large Jupiter trojan from the Greek camp approximately 66 kilometers (41 miles) in diameter. It was discovered on 15 December 1998, by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.^[1] The dark asteroid has a rotation period of 17.4 hours and possibly a spherical shape.^[4] The body is one of the 50 largest Jupiter trojans.^[1] It was named from Greek mythology after the Achaean soldier Iphinous who was killed by Glaucus in the Trojan War.^[2]

Iphinous is a 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). It is also a non-family asteroid in the Jovian background population.^[6][13] The asteroid orbits the Sun at a distance of 4.9–5.6 AU once every 11 years and 11 months (4,345 days; semi-major axis of 5.21 AU). Its orbit has an eccentricity of 0.07 and an inclination of 24° with respect to the ecliptic.^[3]

The body's observation arc begins with a precovery taken at the Siding Spring Observatory in February 1991, nearly 8 years prior to its official discovery observation at Socorro.^[1]

This minor planet was numbered on 31 August 1999 (M.P.C. 35589).^[14] On 14 May 2021, the object was named by the Working Group for Small Bodies Nomenclature (WGSBN) after Iphinous from Greek mythology. An Achaean soldier who participated in the Trojan War, Iphinous was killed by Glaucus in hand-to-hand combat during the siege of Troy.^[2]

Iphinous is a generically assumed C-type asteroid.^[4] Many if not most Jupiter trojans show an even darker D or P-type spectrum.