11395 Iphinous (provisional designation1998 XN₇₇) is a largeJupiter trojan from theGreek camp approximately 66 kilometers (41 miles) in diameter. It was discovered on 15 December 1998, by astronomers with theLincoln Near-Earth Asteroid Research at theLincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.^[1] The darkasteroid has arotation period of 17.4 hours and possibly a spherical shape.^[4] The body is one of the50 largest Jupiter trojans.^[1] It was named from Greek mythology after the Achaean soldierIphinous who was killed byGlaucus in theTrojan War.^[2]

Iphinous is a Jovianasteroid orbiting in the leading Greek camp at Jupiter'sL₄Lagrangian point, 60° ahead of the Gas Giant's orbit in a1:1 resonance(seeTrojans in astronomy). It is also a non-family asteroid in theJovian 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 aneccentricity of 0.07 and aninclination of 24° with respect to theecliptic.^[3]

The body'sobservation arc begins with aprecovery taken at theSiding Spring Observatory in February 1991, nearly 8 years prior to its official discovery observation at Socorro.^[1]

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

Iphinous is a generically assumedC-type asteroid.^[4] Many if not most Jupiter trojans show an even darkerD orP-type spectrum.

In 2009 and 2010, two fragmentarylightcurves of Iphinous were obtained fromphotometric observations byStefano Mottola at theCalar Alto Observatory in Spain. Lightcurve analysis gave a tentativerotation period of 13.696 and 13.70 hours with a brightness variation of 0.14 and 0.06magnitude, respectively (U=2-/1+).^[10]

During 2015–2017, three additional photometric observation were made at the CalifornianCenter for Solar System Studies byRobert Stephens, Daniel Coley andBrian Warner in collaboration with Linda French fromIllinois Wesleyan University. The two best-rated lightcurves gave a period of 17.383 and 17.44 with an amplitude of 0.08 and 0.11 magnitude, respectively, indicating that the body has a nearly spherical shape (U=3-/3-).^[11][12][a]

According to the surveys carried out by the JapaneseAkari satellite, the Infrared Astronomical SatelliteIRAS, and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, Iphinous measures between 64.71 and 68.98 kilometers in diameter and its surface has analbedo between 0.045 and 0.067.^[7][8][9]

TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0510 and a diameter of 64.51 kilometers based on anabsolute magnitude of 9.8.^[4]

• Asteroid Lightcurve Database (LCDB), query form (infoArchived 16 December 2017 at theWayback Machine)
• Discovery Circumstances: Numbered Minor Planets (10001)-(15000) – Minor Planet Center
• 11395 Iphinous atAstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 11395 Iphinous at theJPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Jupiter trojans (Greek camp)
• Background asteroids
• Discoveries by LINEAR
• Named minor planets
• Astronomical objects discovered in 1998

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• JPL Small-Body Database ID different from Wikidata