34746 Thoon (provisional designation2001 QE₉₁) is a darkJupiter trojan from theTrojan camp, approximately 60 kilometers (37 miles) in diameter. It was discovered on 22 August 2001, by astronomers with theLincoln Near-Earth Asteroid Research atLincoln Lab's ETS in Socorro, New Mexico.^[1] The possibly elongated Jovianasteroid is one of the70 largest Jupiter trojans and has arotation period of 19.6 hours.^[9] It was named after the Trojan warriorThoön from Greek mythology.^[2]

Thoon is a darkJupiter trojan in a 1:1orbital resonance with Jupiter. It is located in the traileringTrojan camp at the Gas Giant'sL₅Lagrangian point, 60° behind its orbit(seeTrojans in astronomy).^[4] It is also a non-family asteroid of theJovian background population.^[5]

It orbits the Sun at a distance of 5.0–5.4 AU once every 11 years and 9 months (4,287 days;semi-major axis of 5.16 AU). Its orbit has aneccentricity of 0.04 and aninclination of 27° with respect to theecliptic.^[3] The body'sobservation arc begins with its first observation as1949 KS at theGoethe Link Observatory in November 1945, almost 56 years prior to its official discovery observation at Socorro.^[1]

Thisminor planet wasnumbered on 28 January 2002 (M.P.C. 22480).^[11] On 14 May 2021, the object was named by theWorking Group for Small Bodies Nomenclature (WGSBN), afterThoön, aLycian warrior and ally of the Trojans, who was killed in battle byOdysseus during theTrojan War.^[2]

Thoon'is an assumedC-type asteroid. ItsV–I color index of 0.95 is typical for mostD-type asteroids, the dominantspectral type among the Jupiter trojans.^[9]

In April 2007, a rotationallightcurve of Thoon was obtained fromphotometric observations byLawrence Molnar atCalvin University, using theCalvin-Rehoboth Robotic Observatory in New Mexico. Lightcurve analysis gave a well-definedrotation period of19.633±0.002 hours with a high brightness variation of 0.56magnitude (U=3).^[9][8] A high amplitude is indicative of a non-spherical shape.

According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, Thoon measures between 61.68 and 63.63 kilometers in diameter and its surface has analbedo between 0.061 and 0.091.^[6][7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.0580 and calculates a diameter of 60.51 kilometers based on anabsolute magnitude of 9.8.^[9]

• Asteroid Lightcurve Database (LCDB), query form (infoArchived 16 December 2017 at theWayback Machine)
• Dictionary of Minor Planet Names, Google books
• Discovery Circumstances: Numbered Minor Planets (30001)-(35000) – Minor Planet Center
• Asteroid (34746) 2001 QE91 at the Small Bodies Data Ferret
• 34746 Thoon atAstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 34746 Thoon at theJPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Jupiter trojans (Trojan camp)
• Discoveries by LINEAR
• Named minor planets
• Astronomical objects discovered in 2001

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• Articles with short description
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• JPL Small-Body Database ID different from Wikidata