1870 Glaukos (// GLAW-kəs), provisional designation 1971 FE, is a mid-sized Jupiter trojan from the Trojan camp, approximately 47 kilometers (29 miles) in diameter. Discovered during the first Palomar–Leiden Trojan survey in 1971, it was later named for Glaucus from Greek mythology. The dark D-type asteroid has a rotation period of 6.0 hours.
|Discovered by||C. J. van Houten|
I. van Houten-G.
|Discovery site||Palomar Obs.|
|Discovery date||24 March 1971|
|MPC designation||(1870) Glaukos|
|Pronunciation||// · GLAW-kəs|
|1971 FE · 1976 SM|
|Jupiter trojan |
Trojan  · background 
|Orbital characteristics |
|Epoch 23 March 2018 (JD 2458200.5)|
|Uncertainty parameter 0|
|Observation arc||62.50 yr (22,827 d)|
|12.02 yr (4,389 d)|
|0° 4m 55.2s / day|
|Jupiter MOID||0.1272 AU|
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 California. The body's observation arc begins with a precovery of its first recorded observation at Palomar in November 1955, or more than 15 years prior to its official discovery observation.
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 7000 Jupiter trojans have already been discovered.
Orbit and classificationEdit
Glaukos 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 its orbit . It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 5.1–5.4 AU once every 12.02 years (4,389 days; semi-major axis of 5.25 AU). Its orbit has an eccentricity of 0.03 and an inclination of 7° with respect to the ecliptic.
Glaukos has been characterized as a dark D-type asteroid by PanSTARRS' photometric survey as well as in the SDSS-based taxonomy. It is the most common spectral type among the Jupiter trojans.
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 of 5.979, 5.980 and 5.989 hours with an amplitude between 0.27 and 0.37 magnitude (U=2/2/2).
In October 2013, photometric observations by American astronomer Robert Stephens at the Center for Solar System Studies gave the so-far best rated lightcurve, with a period of 5.986±0.003 hours and a brightness variation of 0.42 magnitude (U=3).[a]
Diameter and albedoEdit
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Glaukos measures 47.65 kilometers in diameter, and its surface has an albedo of 0.049, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 42.23 kilometers with an absolute magnitude of 10.6.
This minor planet was named after Glaucus (Glaukos) from Greek mythology. In Homer's Iliad, he was captain in the Lycian contingent during the Trojan War. and was killed by Ajax, after whom the Jovian asteroid 1404 Ajax is named. The official naming citation was published by the Minor Planet Center on 1 June 1975 (M.P.C. 3826).
- "1870 Glaukos (1971 FE)". Minor Planet Center. Retrieved 21 June 2018.
- Schmadel, Lutz D. (2007). "(1870) Glaukos". Dictionary of Minor Planet Names – (1870) Glaukos. Springer Berlin Heidelberg. p. 150. doi:10.1007/978-3-540-29925-7_1871. ISBN 978-3-540-00238-3.
- "JPL Small-Body Database Browser: 1870 Glaukos (1971 FE)" (2018-05-24 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2018.
- "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 21 June 2018.
- "Asteroid (1870) Glaukos – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 20 October 2019.
- 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. Retrieved 21 June 2018. (online catalog)
- 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 21 June 2018.
- "LCDB Data for (1870) Glaukos". Asteroid Lightcurve Database (LCDB). Retrieved 21 June 2018.
- 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:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007.
- Carvano, J. M.; Hasselmann, P. H.; Lazzaro, D.; Mothé-Diniz, T. (February 2010). "SDSS-based taxonomic classification and orbital distribution of main belt asteroids". Astronomy and Astrophysics. 510: 12. Bibcode:2010A&A...510A..43C. doi:10.1051/0004-6361/200913322. Retrieved 21 June 2018.
- "Asteroid 1870 Glaukos". Small Bodies Data Ferret. Retrieved 20 October 2019.
- 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:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75.
- Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 1870 Glaukos at AstDyS-2, Asteroids—Dynamic Site
- 1870 Glaukos at the JPL Small-Body Database