12238 Actor

Asteroid July 2018 yes 12238 Actor #C2FFFF E. W. ElstG. Pizarro La Silla Obs. 17 December 1987 (12238) Actor 1987 YU 11986 WW 8 ˈ æ k t ɔr Actor (Greek mythology) Jupiter trojanGreekbackground 23 March 2018 (JD 2458200.5) 0 31.47 yr (11,494 d) 5.8135 AU 4.5361 AU 5.1748 AU 0.1234 11.77 yr (4,300 d) 245.58° 0.0837 ms / day 21.091° 227.59° 177.30° 0.4056 AU 2.8520 30.25 4.84 km36.78 km (calculated) 7.284 h 0.057 (assumed)0.092 0.017 C (assumed) 10.8010.9 12238 Actor ˈ æ k t ɔr is a Jupiter trojan from the Greek camp, approximately 30 km mi off 2 us in diameter. It was discovered on 17 December 1987, by astronomers Eric Elst and Guido Pizarro at the La Silla Observatory in northern Chile. The dark Jovian asteroid has a rotation period of 7.3 hours. It was named after Actor, father of the heroes Eurytus and Cteatus from Greek mythology. Orbit and classification As all Jupiter trojans, Actor is in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at the Gas Giant's Lagrangian point, 60° ahead on its orbit (see Trojans in astronomy). It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 4.5–5.8 AU once every 11 years and 9 months (4,300 days; semi-major axis of 5.17 AU). Its orbit has an eccentricity of 0.12 and an inclination of 21° with respect to the ecliptic. The body's observation arc begins with its first observation as 1986 WW 8 at the Kiso Observatory in November 1986, or 13 months prior to its official discovery observation at La Silla. Naming This minor planet was named from Greek mythology after Actor (son of Phorbas and Hyrmine), the alleged father of the twin brothers Eurytus and Cteatus, who beat Nestor, king of Pylos, in a chariot race. The official naming citation was published by the Minor Planet Center on 6 January 2003 (M.P.C. 47300). Physical characteristics Actor is an assumed C-type asteroid, while the majority of larger Jupiter trojans are D-types. Rotation period In 2007, a rotational lightcurve of Actor was obtained from photometric observations at the Sierra Nevada Observatory, using its 1.5-meter telescope. Lightcurve analysis gave a rotation period of 7.284 hours with a brightness variation of 0.30 magnitude (U=2). The same group also published a period determination of 7.28 0.02 hours with an amplitude of 0.33 magnitude in 2010. In July and August 2015, observations by the Kepler space telescope during its K2 mission gave another two lightcurves with a concurring period of 7.28 and 7.281 hours, respectively. Both measurements had a brightness variation of 0.29 magnitude (U=2/2). Diameter and albedo According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Actor measures 30.25 kilometers in diameter and its surface has an albedo of 0.092, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 36.78 kilometers based on an absolute magnitude of 10.9. References 30em 2018-05-20 last obs. JPL Small-Body Database Browser: 12238 Actor (1987 YU1) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2012238 Jet Propulsion Laboratory 5 July 2018 12238 Actor (1987 YU1) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=12238 5 July 2018 List of Jupiter Trojans Minor Planet Center V. Carruba 1 July 2018 https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html 5 July 2018 MPC/MPO/MPS Archive Minor Planet Center https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html 5 July 2018 T. Grav A. K. Mainzer J. M. Bauer J. R. Masiero C. R. Nugent November 2012 WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy The Astrophysical Journal 759 1 10 2012ApJ...759...49G 10.1088/0004-637X/759/1/49 1209.1549 119101711 (online catalog) Asteroid (12238) Actor – Proper Elements AstDyS-2, Asteroids – Dynamic Site https://newton.spacedys.com/astdys/index.php?n=12238&pc=1.1.6 5 July 2018 12238 5 July 2018 R. D. Duffard M. Melita J. L. Ortiz J. Licandro I. P. Williams D. Jones December 2007 Light-Curve Survey of the Trojan Asteroids https://www.lpi.usra.edu/meetings/acm2008/pdf/8187.pdf Asteroids 1405 8187 2008LPICo1405.8187D 5 July 2018 M. D. Melita R. Duffard I. P. Williams D. C. Jones J. Licandro J. L. Ortiz June 2010 Lightcurves of 6 Jupiter Trojan asteroids Planetary and Space Science 58 7–8 1035–1039 2010P&SS...58.1035M 10.1016/j.pss.2010.03.009 Erin Lee Ryan Benjamin N. L. Sharkey Charles E. Woodward March 2017 Trojan Asteroids in the Kepler Campaign 6 Field The Astronomical Journal 153 3 12 2017AJ....153..116R 10.3847/1538-3881/153/3/116 125570438 free 6 Gy. M. Szabó A. Pál Cs. Kiss L. L. Kiss L. Molnár O. Hanyecz E. Plachy K. Sárneczky R. Szabó March 2017 The heart of the swarm: K2 photometry and rotational characteristics of 56 Jovian Trojan asteroids Astronomy and Astrophysics 599 13 2017A&A...599A..44S 10.1051/0004-6361/201629401 1609.02760 119275951 External links Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books Discovery Circumstances: Numbered Minor Planets (10001)-(15000) – Minor Planet Center Asteroid 12238 Actor https://web.archive.org/web/20180705033225/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=12238%20Actor 5 July 2018 at the Small Bodies Data Ferret 12238 12237 Coughlin 12238 12239 Carolinakou 012238 Category:Discoveries by Eric Walter Elst Category:Discoveries by Guido Pizarro (astronomer) Category:Named minor planets 19871217