1870 Glaukos

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1870 Glaukos
Discovery [1]
Discovered by C. J. van Houten
I. van Houten-G.
T. Gehrels
Discovery site Palomar Obs.
Discovery date 24 March 1971
MPC designation (1870) Glaukos
Pronunciation /ˈɡlɔːkəs/ GLAW-kəs
Named after
(Greek mythology)[2]
1971 FE · 1976 SM
Jupiter trojan[3]
(Trojan camp)[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 61.35 yr (22,407 days)
Aphelion 5.4149 AU
Perihelion 5.0778 AU
5.2464 AU
Eccentricity 0.0321
12.02 yr (4,389 days)
0° 4m 55.2s / day
Inclination 6.5762°
Jupiter MOID 0.1257 AU
TJupiter 2.9860
Physical characteristics
Dimensions 40.33 km (calculated)[5]
5.979±0.0052 h[8]
5.980±0.0093 h[8]
5.986±0.003 h[9]
5.989±0.0205 h[8]
0.057 (assumed)[5]
D[10] · C[5]
10.5[6] · 10.6[1][5] · 10.659±0.004 (R)[8] · 10.83±0.34[10]

1870 Glaukos (/ˈɡlɔːkəs/ GLAW-kəs), provisional designation 1971 FE, is a carbonaceous Jupiter trojan from the Trojan camp, approximately 45 kilometers in diameter. Discovered during the Palomar–Leiden Trojan survey in 1971, it was later named for Glaucus from Greek mythology.


Glaukos was discovered on 24 March 1971, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by astronomer Tom Gehrels at the Californian Palomar Observatory in the United States.[3]

This discovery was made in the context of a larger survey of faint Trojans, the trio of Dutch and Dutch–American astronomers also collaborated on the productive Palomar–Leiden survey in the 1960s, using the same procedure as for this (smaller) survey: Tom Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Cornelis and Ingrid van Houten at Leiden Observatory where astrometry was carried out.

More than 6,200 Jupiter trojans have already been discovered.[4]

Orbit and classification[edit]

This Trojan asteroid dwells in the L5 Lagrangian point, 60° behind Jupiter in the so-called Trojan camp.[4] It orbits the Sun at a distance of 5.1–5.4 AU once every 12.02 years (4,389 days). Its orbit has an eccentricity of 0.03 and an inclination of 7° with respect to the ecliptic.[1]

Physical characteristics[edit]

Glaukos has been characterized as a D-type asteroid by PanSTARRS' photometric survey.[10]


In 2012 and 2013, three rotational lightcurves of Glaukos in the R- and S-band were obtained by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period between 5.979 and 5.989 hours with an amplitude of 0.27 to 0.37 magnitude (U=2/2/2)[8]

In October 2013, photometric observations by American astronomer Robert Stephens gave the so-far best rated lightcurve, with a period of 5.986 hours and a brightness variation of 0.42 magnitude (U=3).[9]

Diameter and albedo[edit]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Glaukos measures 47.649 kilometers in diameter, and its surface has an albedo of 0.049,[6][7] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous C-type asteroids of 0.057 and calculates a diameter of 40.33 kilometers with an absolute magnitude of 10.6.[5]


This minor planet was named after Glaucus (Glaukos) from Greek mythology; in Homer's Iliad, he was captain in the Lycian army during the Trojan War and was killed by Ajax, after whom the minor planet 1404 Ajax is named.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3826).[11]


  1. ^ a b c d "JPL Small-Body Database Browser: 1870 Glaukos (1971 FE)" (2017-03-30 last obs.). Jet Propulsion Laboratory. Retrieved 9 June 2017. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1870) Glaukos. Springer Berlin Heidelberg. p. 150. ISBN 978-3-540-00238-3. Retrieved 12 December 2016. 
  3. ^ a b "1870 Glaukos (1971 FE)". Minor Planet Center. Retrieved 12 December 2016. 
  4. ^ a b c "List of Jupiter Trojans". Minor Planet Center. 20 August 2016. Retrieved 12 December 2016. 
  5. ^ a b c d e "LCDB Data for (1870) Glaukos". Asteroid Lightcurve Database (LCDB). Retrieved 12 December 2016. 
  6. ^ 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 12 December 2016. 
  7. ^ 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. 
  8. ^ a b c d e 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 12 December 2016. 
  9. ^ a b Stephens, Robert D.; French, Linda M.; Davitt, Chelsea; Coley, Daniel R. (April 2014). "At the Scaean Gates: Observations Jovian Trojan Asteroids, July- December 2013". The Minor Planet Bulletin. 41 (2): 95–100. Bibcode:2014MPBu...41...95S. ISSN 1052-8091. Retrieved 12 December 2016. 
  10. ^ a b c 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 12 December 2016. 
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 12 December 2016. 

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