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
Pronunciation /pɒˈlɪdəməs/ pol-ID-ə-məs
Named after
(Greek mythology)[2]
1988 RU · 1977 SP1
1977 TV4 · 1983 GJ
1988 PK4
Jupiter trojan[3]
(Trojan camp)[4]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 62.49 yr (22,825 days)
Aphelion 5.7517 AU
Perihelion 4.7305 AU
5.2411 AU
Eccentricity 0.0974
12.00 yr (4,383 days)
Inclination 7.9575°
Physical characteristics
Dimensions 66.92 km (calculated)[3]
80 km (generic)[5][6]
82.032±0.626 km[7][8]
87.51±5.02 km[9]
9.88±0.01 h[10]
9.908±0.018 h[11]
9.9214±0.0085 h[12]
9.941±0.006 h[13]
0.057 (assumed)[3]
9.20[9] · 9.526±0.002 (R)[12] · 9.6[1][3] · 9.75[7][14] · 9.86±0.17[15]

4348 Poulydamas, provisional designation 1988 RU, is a large carbonaceous Jupiter Trojan from the Trojan camp, approximately 80 kilometers in diameter. It was discovered by American astronomer Carolyn Shoemaker at the U.S. Palomar Observatory in California, on 11 September 1988.[16]

The dark C-type asteroid orbits the Sun in the Trojan camp at a distance of 4.7–5.8 AU once every 12 years (4,382 days). Its orbit has an eccentricity of 0.10 and an inclination of 8° with respect to the plane of the ecliptic.[1]

In December 1990, astronomers Stefano Mottola and Mario Di Martino used photometric observations made with the 1.52-meter Loiano Telescope at the Observatory of Bologna, Italy, to build a light-curve for this asteroid. It gave a rotation period of 9.908±0.018 hours with a brightness variation of 0.21±0.01 magnitude (U=3).[11] In October 2013, observations at the Palomar Transient Factory gave a period of 9.9214 hours with an amplitude of 0.23 magnitude (U=2).[12] In January 2015 and 2016, astronomer Robert D. Stephens at the Center for Solar System Studies (CS3) obtained two rotational light-curves that gave a period of 9.88±0.01 and 9.941±0.006 hours with a brightness variation of 0.19 and 0.27, respectively (U=3-/3-).[10][13]

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][7][8][9]

The minor planet was named after Poulydamas from Greek mythology, the closest counsellor and strategist of the Trojan prince Hector, after whom the minor planet 624 Hektor is named. Hector and Poulydamas were born on the same night. While the gods gave Hector the ability to perfectly master his arms, Poulydamas was given the present of better judgment. It was Poulydamas who urged to lock the gates of Troy against Achilles (also see 588 Achilles), but Hector left the city and confronted Achilles nonetheless, which led to his doom and to the eventual downfall of Troy.[2] Naming citation was published on 28 April 1991 (M.P.C. 18141).[17]


  1. ^ a b c d "JPL Small-Body Database Browser: 4348 Poulydamas (1988 RU)" (2016-04-28 last obs.). Jet Propulsion Laboratory. Retrieved 5 December 2016. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4348) Poulydamas. Springer Berlin Heidelberg. p. 373. ISBN 978-3-540-00238-3. Retrieved 5 December 2016. 
  3. ^ a b c d e f "LCDB Data for (4348) Poulydamas". Asteroid Lightcurve Database (LCDB). Retrieved 5 December 2016. 
  4. ^ "List of Jupiter Trojans". Minor Planet Center. 20 June 2016. Retrieved 5 December 2016. 
  5. ^ 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. 
  6. ^ 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. 
  7. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 5 December 2016. 
  8. ^ 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 5 December 2016. 
  9. ^ a b c d 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" (PDF). Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 5 December 2016. 
  10. ^ 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. Retrieved 8 January 2016. 
  11. ^ 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 5 December 2016. 
  12. ^ a b c 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:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 8 January 2016. 
  13. ^ a b Stephens, Robert D.; Coley, Daniel R.; French, Linda M. (July 2016). "A Report from the L5 Trojan Camp - Lightcurves of Jovian Trojan Asteroids from the Center for Solar System Studies". The Minor Planet Bulletin. 43 (3): 265–270. Bibcode:2016MPBu...43..265S. ISSN 1052-8091. Retrieved 5 December 2016. 
  14. ^ Schaefer, Martha W.; Schaefer, Bradley E.; Rabinowitz, David L.; Tourtellotte, Suzanne W. (June 2010). "Phase curves of nine Trojan asteroids over a wide range of phase angles". Icarus. 207 (2): 699–713. Bibcode:2010Icar..207..699S. doi:10.1016/j.icarus.2009.11.031. Retrieved 5 December 2016. 
  15. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 5 December 2016. 
  16. ^ "4348 Poulydamas (1988 RU)". Minor Planet Center. Retrieved 5 December 2016. 
  17. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 5 December 2016. 

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