11887 Echemmon

Trojan asteroid July 2018 yes 11887 Echemmon #C2FFFF F. BörngenL. D. Schmadel Karl Schwarzschild Obs. 14 October 1990 (11887) Echemmon 1990 TV 121989 SX 13 ᵻ ˈ k ɛ m ɒ n Ἐχέμμων Echemmōn(Greek mythology) Jupiter trojanTrojanbackground 23 March 2018 (JD 2458200.5) 0 63.26 yr (23,105 d) 5.6556 AU 4.7089 AU 5.1823 AU 0.0913 11.80 yr (4,309 d) 171.52° 0.0835 ms / day 24.044° 242.65° 112.06° 0.0514 AU 2.8190 31.19 0.49 km38.51 km (calculated) 8.47 0.01 hlightcurve-plots-CS3 0.057 (assumed)0.095 0.008 C (assumed) 10.7010.8 11887 Echemmon ᵻ ˈ k ɛ m ɒ n is a Jupiter trojan from the Trojan camp, approximately 31 km mi off 2 us in diameter. It was discovered on 14 October 1990, by German astronomers Freimut Börngen and Lutz Schmadel at the Karl Schwarzschild Observatory in Tautenburg, Germany. The dark Jovian asteroid has a rotation period of 8.5 hours. It was named after the Trojan hero Echemmon from Greek mythology. Orbit and classification As all Jupiter trojans, Echemmon is in a 1:1 orbital resonance with Jupiter. It is located in the trailering Trojan camp at the Gas Giant's Lagrangian point, 60° behind 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 4.7–5.7 AU once every 11 years and 10 months (4,309 days; semi-major axis of 5.18 AU). Its orbit has an eccentricity of 0.09 and an inclination of 24° with respect to the ecliptic. The body's observation arc begins with a precovery taken at the Palomar Observatory in November 1954, nearly 36 years prior to its official discovery observation at Tautenburg. Naming This minor planet was named from Greek mythology after the Trojan prince Echemmon, one of the many sons of King Priam of Troy. He was slain together with his brother Chromius by Diomedes, king of Argos, during the Trojan War. The name was suggested by the first discoverer, Freimut Börngen, and published by the Minor Planet Center on 9 March 2001 (M.P.C. 42361). Physical characteristics Echemmon is an assumed C-type asteroid, while most larger Jupiter trojans are D-types. Rotation period In November 2013, a rotational lightcurve of Echemmon was obtained over three nights of photometric observations by Robert Stephens at the Center for Solar System Studies in Landers, California. Lightcurve analysis gave a rotation period of 8.47 0.01 hours with a brightness amplitude of 0.15 magnitude (U=2).lightcurve-plots-CS3 Diameter and albedo According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Echemmon measures 31.19 kilometers in diameter and its surface has an albedo of 0.095, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 38.51 kilometers based on an absolute magnitude of 10.8. Notes lightcurve-plots-CS3 Lightcurve plots of (11887) Echemmon from Nov 2013 by Robert Stephens at the Center for Solar System Studies U81. Quality code is 2- (lightcurve rating at CS3). Summary figures at the LCDB and CS3. References 30em 2018-02-25 last obs. JPL Small-Body Database Browser: 11887 Echemmon (1990 TV12) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2011887 Jet Propulsion Laboratory 4 July 2018 11887 Echemmon (1990 TV12) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=11887 4 July 2018 List of Jupiter Trojans Minor Planet Center V. Carruba 1 July 2018 https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html 4 July 2018 MPC/MPO/MPS Archive Minor Planet Center https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html 4 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 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759...49G The Astrophysical Journal 759 1 10 2012ApJ...759...49G 10.1088/0004-637X/759/1/49 1209.1549 119101711 4 July 2018 (online catalog) Asteroid (11887) Echemmon – Proper Elements AstDyS-2, Asteroids – Dynamic Site https://newton.spacedys.com/astdys/index.php?n=11887&pc=1.1.6 4 July 2018 11887 4 July 2018 Robert D. Stephens Linda M. French Chelsea Davitt Daniel R. Coley April 2014 At the Scaean Gates: Observations Jovian Trojan Asteroids, July- December 2013 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014MPBu...41...95S The Minor Planet Bulletin 41 2 95–100 1052-8091 2014MPBu...41...95S 4 July 2018 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 11887 Echemmon https://web.archive.org/web/20180705004249/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=11887+Echemmon 5 July 2018 at the Small Bodies Data Ferret 11887 2011887 11886 Kraske 11887 (11888) 1990 UD3 011887 Category:Discoveries by Freimut Börngen Category:Discoveries by Lutz D. Schmadel Category:Named minor planets 19901014