4348 Poulydamas

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4348 Poulydamas
Discovery [1]
Discovered by C. S. Shoemaker
Discovery site Palomar Obs.
Discovery date 11 September 1988
MPC designation 4348 Poulydamas
Named after
(Greek mythology)[2]
1988 RU · 1977 SP1
1977 TV4 · 1983 GJ
1988 PK4
Jupiter trojan[3]
Orbital characteristics[1]
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc 62.14 yr (22,695 days)
Aphelion 5.7549 AU
Perihelion 4.7256 AU
5.2403 AU
Eccentricity 0.0982
12.00 yr (4,382 days)
Inclination 7.9578°
Physical characteristics
Dimensions 87.51±5.02 km[4]
82.03±0.63 km[5]
66.92 km (calculated)[3]
80 km (generic)[6][7]
9.908±0.018 h[8]
9.9214±0.0085 h[9]
9.88±0.01 h[10]
0.057 (assumed)[3]

4348 Poulydamas, provisional designation 1988 RU, is a large carbonaceous Jupiter Trojan, about 80 kilometers in diameter. It was discovered by American female astronomer Carolyn Shoemaker at the U.S. Palomar Observatory in California, on 11 September 1988.[11]

The dark C-type asteroid orbits the Sun in the Trojan camp at a distance of 4.7–5.8 AU once every 12.00 years (4,382 days). Its orbit shows an eccentricity of 0.10 and is tilted by 8 degrees to the plane of the ecliptic.[1] During 1990, photometric observations of this asteroid were used to build a light-curve showing a rotation period of 9.908±0.018 hours with a brightness variation of 0.21±0.01 magnitude.[8]

Based on the surveys carried out by the Japanese Akari and the NEOWISE mission of the U.S. Wide-field Infrared Survey Explorer, the asteroid has a very low albedo of 0.048 and 0.033, while the Collaborative Asteroid Lightcurve Link (CALL) assumes a somewhat higher albedo of 0.057 for the carbonaceous body. Accordingly, CALL calculates the asteroid's diameter to be only 67 kilometers while the two space-based surveys gave a larger diameter of 82 and 88 kilometers, respectively.[3][4][5]

The minor planet was named after Poulydamas from Greek mythology, the most trusted strategist and advisor of the Trojan prince Hector, after whom the minor planet 624 Hektor is named, and who was born on the same night as Poulydamas. The gods gave Hektor skill with arms and gave Poulydamas better judgment. He sensibly advised Hektor to lock the gates of Troy against Achilles (also see 588 Achilles), but Hector disregarded his friend's advice and went out of the city to his doom and to the eventual doom of Troy.[2]


  1. ^ a b c d "JPL Small-Body Database Browser: 4348 Poulydamas (1988 RU)" (2015-12-20 last obs.). Jet Propulsion Laboratory. Retrieved 8 January 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4399) Ashizuri. Springer Berlin Heidelberg. p. 373. ISBN 978-3-540-29925-7. Retrieved 8 January 2016. 
  3. ^ a b c d e "LCDB Data for (4348) Poulydamas". Asteroid Lightcurve Database (LCDB). Retrieved 8 January 2016. 
  4. ^ a b c Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 8 January 2016. 
  5. ^ a b c Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407free to read. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 8 January 2016. 
  6. ^ Fernández, Yanga R.; Sheppard, Scott S.; Jewitt, David C. (September 2003). "The Albedo Distribution of Jovian Trojan Asteroids". The Astronomical Journal. 126 (3): 1563–1574. Bibcode:2003AJ....126.1563F. doi:10.1086/377015. Retrieved 8 January 2016. 
  7. ^ Dan Bruton. "Conversion of Absolute Magnitude to Diameter for Minor Planets". Department of Physics & Astronomy (Stephen F. Austin State University). Archived from the original on 17 February 2009. Retrieved 2009-01-20. 
  8. ^ a b Mottola, Stefano; Di Martino, Mario; Erikson, Anders; Gonano-Beurer, Maria; Carbognani, Albino; Carsenty, Uri; et al. (May 2011). "Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects". The Astronomical Journal. 141 (5): 32. Bibcode:2011AJ....141..170M. doi:10.1088/0004-6256/141/5/170. Retrieved 8 January 2016. 
  9. ^ Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041free to read. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 8 January 2016. 
  10. ^ 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. Retrieved 8 January 2016. 
  11. ^ "4348 Poulydamas (1988 RU)". Minor Planet Center. Retrieved 8 January 2016. 

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