18493 Demoleon

From Wikipedia, the free encyclopedia
18493 Demoleon
Discovery [1]
Discovered byE. W. Elst
Discovery siteLa Silla Obs.
Discovery date17 April 1996
Designations
(18493) Demoleon
Pronunciation/dɪˈmoʊliən/[5]
Named after
Δημολέων Dēmoleōn[1]
(Greek mythology)
1996 HV9 · 2000 RZ31
Minor planet category
Jupiter trojan [1][2]
Trojan [3] · background [4]
Orbital characteristics [2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc28.31 yr (10,339 d)
Aphelion5.7852 AU
Perihelion4.8105 AU
5.2979 AU
Eccentricity0.0920
12.19 yr (4,454 d)
210.34°
0° 4m 50.88s / day
Inclination17.198°
215.55°
89.277°
Jupiter MOID0.2104 AU
TJupiter2.9020
Physical characteristics
Mean diameter
33.47±0.45 km[6]
40.33 km (calculated)[7]
14.43±0.01 h[8][a]
0.057 (assumed)[7]
0.083±0.013[6]
C (assumed)[7]
B–V = 0.703±0.073[9]
V–R = 0.395±0.047[9]
V–I = 0.775±0.073[9]
Absolute magnitude (H)
10.70[1][2][7][6]

18493 Demoleon /dɪˈmoʊliən/ is a Jupiter trojan from the Trojan camp, approximately 33 kilometers (21 miles) in diameter. It was discovered by Belgian astronomer Eric Elst at ESO's La Silla Observatory in northern Chile on 17 April 1996.[1] The dark Jovian asteroid has a rotation period of 14.4 hours.[7] It was named after the Trojan warrior Demoleon from Greek mythology.[1]

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 L5 Lagrangian point, 60° behind on its orbit (see Trojans in astronomy). It is also a non-family asteroid of the Jovian background population.[4] 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.[2] 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.[1]

Naming[]

This minor planet was named from Greek mythology after the Trojan warrior Demoleon, son of Antenor (2207 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.[1] The official naming citation was published by the Minor Planet Center on 27 May 2010 (M.P.C. 70409).[10]

Physical characteristics[]

Demoleon is an assumed C-type asteroid, while most larger Jupiter trojans are D-types.[7] It has a low V–I color index of 0.775 (see table below).[9]

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).[8][a]

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,[6] 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.[7]

100+ largest Jupiter trojans

Notes[]

  1. ^ Jump up to: a b 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[]

  1. ^ Jump up to: a b c d e f g h "18493 Demoleon (1996 HV9)". Minor Planet Center. Retrieved 4 July 2018.
  2. ^ Jump up to: a b c d "JPL Small-Body Database Browser: 18493 Demoleon (1996 HV9)" (2018-02-24 last obs.). Jet Propulsion Laboratory. Retrieved 4 July 2018.
  3. ^ "List of Jupiter Trojans". Minor Planet Center. 1 July 2018. Retrieved 4 July 2018.
  4. ^ Jump up to: a b "Asteroid (18493) Demoleon – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 4 July 2018.
  5. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  6. ^ Jump up to: a b c d Grav, T.; Mainzer, A. K.; Bauer, J. M.; Masiero, J. R.; Nugent, C. R. (November 2012). "WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy". The Astrophysical Journal. 759 (1): 10. arXiv:1209.1549. Bibcode:2012ApJ...759...49G. doi:10.1088/0004-637X/759/1/49. S2CID 119101711. (online catalog)
  7. ^ Jump up to: a b c d e f g "LCDB Data for (18493) Demoleon". Asteroid Lightcurve Database (LCDB). Retrieved 4 July 2018.
  8. ^ Jump up to: a b Stephens, Robert D.; Coley, Daniel R.; French, Linda M. (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. Bibcode:2015MPBu...42R.216S. ISSN 1052-8091.
  9. ^ Jump up to: a b c d Hainaut, O. R.; Boehnhardt, H.; Protopapa, S. (October 2012). "Colours of minor bodies in the outer solar system. II. A statistical analysis revisited". Astronomy and Astrophysics. 546: 20. arXiv:1209.1896. Bibcode:2012A&A...546A.115H. doi:10.1051/0004-6361/201219566. S2CID 54776793.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 July 2018.

External links[]

Retrieved from ""