18493 Demoleon

Main-belt asteroid July 2018 yes 18493 Demoleon #C2FFFF E. W. Elst La Silla Obs. 17 April 1996 (18493) Demoleon 1996 HV 92000 RZ 31 d ᵻ ' m oʊ l i ə nNoah Webster (1884) A Practical Dictionary of the English Language Δημολέων Dēmoleōn(Greek mythology) Jupiter trojanTrojanbackground 23 March 2018 (JD 2458200.5) 0 28.31 yr (10,339 d) 5.7852 AU 4.8105 AU 5.2979 AU 0.0920 12.19 yr (4,454 d) 210.34° 0.0808 ms / day 17.198° 215.55° 89.277° 0.2104 AU 2.9020 33.47 0.45 km40.33 km (calculated) 14.43 0.01 hlightcurve-plots-CS3 0.057 (assumed)0.083 0.013 C (assumed)B–V 0.703 0.073V–R 0.395 0.047V–I 0.775 0.073 10.70 18493 Demoleon (d ᵻ ' m oʊ l i ə nprovisional designation 1996 HV 9) is a Jupiter trojan from the Trojan camp, approximately 33 km mi off 2 us in diameter. It was discovered by Belgian astronomer Eric Elst at ESO's La Silla Observatory in northern Chile on 17 April 1996. The dark Jovian asteroid has a rotation period of 14.4 hours. It was named after the Trojan warrior Demoleon from Greek mythology. Orbit and classification Demoleon is a dark Jovian asteroid 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 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 4.8–5.8 AU once every 12 years and 2 months (4,454 days; semi-major axis of 5.3 AU). Its orbit has an eccentricity of 0.09 and an inclination of 17° with respect to the ecliptic. The body's observation arc begins with a precovery published by the Digitized Sky Survey and taken at Palomar Observatory in November 1989, more than 6 years prior to its official discovery observation at La Silla. Naming This minor planet was named from Greek mythology after the Trojan warrior Demoleon, son of Antenor, who was a counselor to King Priam. Demoleon, a valiant champion of war was killed by Achilles, whose spear struck Demoleon on the temple through his bronze-cheeked helmet, crushing the bone so that the brain inside was shed in all directions. The official naming citation was published by the Minor Planet Center on 27 May 2010 (M.P.C. 70409). Physical characteristics Demoleon is an assumed C-type asteroid, while most larger Jupiter trojans are D-types. It has a low V–I color index of 0.775 (see table below). Rotation period In November 2014, a rotational lightcurve of Demoleon was obtained over a total of seven nights of photometric observations by Robert Stephens at the Center for Solar System Studies in Landers, California. Lightcurve analysis gave a rotation period of 14.43 0.01 hours with a brightness amplitude of 0.18 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, Demoleon measures 33.47 kilometers in diameter and its surface has an albedo of 0.083, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 40.33 kilometers based on an absolute magnitude of 10.7. Notes lightcurve-plots-CS3 Lightcurve plots of (18493) Demoleon from Nov 2014 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 2018-02-24 last obs. JPL Small-Body Database Browser: 18493 Demoleon (1996 HV9) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2018493 Jet Propulsion Laboratory 4 July 2018 18493 Demoleon (1996 HV9) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=18493 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 The Astrophysical Journal 759 1 10 2012ApJ...759...49G 10.1088/0004-637X/759/1/49 1209.1549 119101711 (online catalog) Asteroid (18493) Demoleon – Proper Elements AstDyS-2, Asteroids – Dynamic Site https://newton.spacedys.com/astdys/index.php?n=18493&pc=1.1.6 4 July 2018 18493 4 July 2018 Robert D. Stephens Daniel R. Coley Linda M. French July 2015 Dispatches from the Trojan Camp - Jovian Trojan L5 Asteroids Observed from CS3: 2014 October - 2015 January The Minor Planet Bulletin 42 3 216–224 1052-8091 2015MPBu...42R.216S O. R. Hainaut H. Boehnhardt S. Protopapa October 2012 Colours of minor bodies in the outer solar system. II. A statistical analysis revisited Astronomy and Astrophysics 546 20 2012A&A...546A.115H 10.1051/0004-6361/201219566 1209.1896 54776793 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 (15001)-(20000) – Minor Planet Center Asteroid 18493 Demoleon https://web.archive.org/web/20180704153611/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=18493%20Demoleon 4 July 2018 at the Small Bodies Data Ferret 18493 (18492) 1996 GS2 18493 018493 Category:Discoveries by Eric Walter Elst Category:Named minor planets 19960417