1869 Philoctetes

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1869 Philoctetes
Discovery [1]
Discovered by C. J. van Houten
I. van Houten-G.
T. Gehrels
Discovery site Palomar Obs.
Discovery date 24 September 1960
MPC designation (1869) Philoctetes
Pronunciation /ˌfɪləkˈttz/
Named after
(Greek mythology)[2]
4596 P-L
Jupiter trojan[3]
(Greek camp)[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 56.61 yr (20,677 days)
Aphelion 5.5755 AU
Perihelion 4.8600 AU
5.2178 AU
Eccentricity 0.0686
11.92 yr (4,353 days)
Inclination 3.9745°
Jupiter MOID 0.0807 AU
TJupiter 2.9900
Physical characteristics
Dimensions 22.655±3.404 km[5]

1869 Philoctetes (/ˌfɪləkˈttz/), provisional designation 4596 P-L, is a Jupiter trojan from the Greek camp, approximately 23 kilometers in diameter.

It was discovered on September 24, 1960, by the Dutch and Dutch–American astronomers Cornelis van Houten, Ingrid van Houten-Groeneveld and Tom Gehrels at Palomar Observatory on Palomar Mountain, California.[3] The asteroid was named after Philoctetes from Greek mythology.[2] On the same night, the same group also discovered 1868 Thersites.

Orbit and classification[edit]

Philoctetes orbits in the L4 Lagrangian point of the Sun–Jupiter system, in the "Greek Camp" of Trojan asteroids.[4] It orbits the Sun at a distance of 4.9–5.6 AU once every 11 years and 11 months (4,353 days). Its orbit has an eccentricity of 0.07 and an inclination of 4° with respect to the ecliptic.[1]

Physical characteristics[edit]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Philoctetes measures 22.7 kilometers in diameter, and its surface has an albedo of 0.104.[5]

As of 2017, the body's rotation period and shape remain unknown.[1][6]

Survey designation[edit]

The survey designation P-L stands for Palomar–Leiden, named after Palomar Observatory and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Cornelis Johannes van Houten and Ingrid van Houten-Groeneveld at Leiden Observatory. The trio are credited with several thousand asteroid discoveries.[7]


This minor planet was named after the Greek mythological figure Philoctetes, famed archer and participant in the Trojan War, where he killed Paris, son of the Trojan King Priam.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3826).[8]


  1. ^ a b c d e "JPL Small-Body Database Browser: 1869 Philoctetes (4596 P-L)" (2017-05-05 last obs.). Jet Propulsion Laboratory. Retrieved 9 June 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1869) Philoctetes. Springer Berlin Heidelberg. p. 150. ISBN 978-3-540-00238-3. Retrieved 12 December 2016. 
  3. ^ a b "1869 Philoctetes (4596 P-L)". Minor Planet Center. Retrieved 12 December 2016. 
  4. ^ a b "List of Jupiter Trojans". Minor Planet Center. 20 August 2016. Retrieved 12 December 2016. 
  5. ^ a b c 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:1209.1549Freely accessible. Bibcode:2012ApJ...759...49G. doi:10.1088/0004-637X/759/1/49. Retrieved 12 December 2016. 
  6. ^ "LCDB Data for (1869) Philoctetes". Asteroid Lightcurve Database (LCDB). Retrieved 9 June 2017. 
  7. ^ "Minor Planet Discoverers". Minor Planet Center. 24 April 2016. Retrieved 12 December 2016. 
  8. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 12 December 2016. 

External links[edit]