9712 Nauplius/ˈnɔːpliəs/ is a mid-sizedJupiter trojan from theGreek camp, approximately 33 kilometers (21 miles) in diameter. It was discovered during the secondPalomar–Leiden Trojan survey at thePalomar Observatory in 1973 and later named afterNauplius the Wrecker, from Greek mythology.^[1] The dark Jovianasteroid has arotation period of 19.4 hours.^[8]

Nauplius was discovered on 19 September 1973, by Dutch astronomer coupleIngrid andCornelis van Houten at Leiden, onphotographic plates taken by astronomerTom Gehrels at thePalomar Observatory in California.^[1] The body'sobservation arc begins with its official discovery observation at Palomar.^[1]

Despite being discovered during the secondPalomar–Leiden Trojan survey in 1973,Nauplius has not received a provisionalsurvey designation prefixed with "T-2". The survey was a fruitful collaboration between the Palomar andLeiden observatories during the 1960s and 1970s. Gehrels used Palomar'sSamuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory whereastrometry was carried out. The trio are credited with the discovery ofseveral thousand asteroids.^[9]

Nauplius is a darkJupiter trojan in a 1:1orbital resonance with Jupiter. It is located in the leadingGreek camp at the Gas Giant'sL₄Lagrangian point, 60° ahead on 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 4.6–5.9 AU once every 12 years (4,374 days;semi-major axis of 5.23 AU). Its orbit has aneccentricity of 0.13 and aninclination of 8° with respect to theecliptic.^[3]

Thisminor planet was named afterNauplius, a son ofPoseidon andAmymone. He was a king ofEuboea and the father ofPalamedes, who was killed after a false accusation byOdysseus during theTrojan War. Nauplius revenged the death of his son by placing lights on the cliffs of his kingdom, causing the Greek fleet to shipwreck on its return from Troy.^[1] The official naming citation was published by theMinor Planet Center on 2 April 1999 (M.P.C. 34355).^[10]

Nauplius is an assumedC-type asteroid, while the majority of larger Jupiter trojans areD-types.^[8]

In March 2014, a first rotationallightcurve ofNauplius was obtained fromphotometric observations over a total of eight nights byRobert Stephens at theCenter for Solar System Studies in Landers, California. Lightcurve analysis gave arotation period of19.41±0.02 hours with a relatively high brightness amplitude of 0.48magnitude (U=2).^[7][a]

According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Nauplius measures 33.42 kilometers in diameter and its surface has analbedo of 0.083,^[6] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 38.51 kilometers based on anabsolute magnitude of 10.8.^[8]

• 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 (5001)-(10000) – Minor Planet Center
• Asteroid 9712 Nauplius at the Small Bodies Data Ferret
• 9712 Nauplius atAstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 9712 Nauplius at theJPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Jupiter trojans (Greek camp)
• Discoveries by Cornelis Johannes van Houten
• Discoveries by Ingrid van Houten-Groeneveld
• Discoveries by Tom Gehrels
• Named minor planets
• Astronomical objects discovered in 1973

• Articles with short description
• Short description matches Wikidata
• Use dmy dates from July 2018
• Webarchive template wayback links