|Discovered by||C. J. van Houten|
I. van Houten-G.
|Discovery site||Palomar Obs.|
|Discovery date||25 March 1971|
|MPC designation||(1873) Agenor|
|Pronunciation||// · ə-JEE-nor|
|Agenor (Greek mythology)|
|Jupiter trojan |
Trojan  · background 
|Orbital characteristics |
|Epoch 23 March 2018 (JD 2458200.5)|
|Uncertainty parameter 0|
|Observation arc||47.16 yr (17,227 d)|
|11.97 yr (4,370 d)|
|0° 4m 56.64s / day|
|Jupiter MOID||0.705 AU|
1873 Agenor (// ə-JEE-nor), provisional designation 1971 FH, is a dark Jupiter trojan from the Trojan camp, approximately 53 kilometers (33 miles) in diameter. It was discovered during the Palomar–Leiden Trojan survey in 1971, and later named after Agenor from Greek mythology. The dark Jovian asteroid belongs to the 100 largest Jupiter trojans and has a rotation period of 20.60 hours.
Agenor was discovered on 25 March 1971, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar Observatory in the Palomar Mountain Range, southeast of Los Angeles.
The discovery was made in a survey of faint Trojans, one night after the discovery of 1870 Glaukos. 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.
Orbit and classification
Agenor 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 4.7–5.7 AU once every 11 years and 12 months (4,370 days; semi-major axis of 5.23 AU). Its orbit has an eccentricity of 0.09 and an inclination of 22° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Palomar in March 1971.
In February 1994, photometric observations with the ESO 1-metre telescope by astronomer Stefano Mottola and Anders Erikson at La Silla Observatory in Chile, were used to build a rotational lightcurve showing a rotation period of 20.60±0.03 hours with a brightness variation of 0.08±0.01 in magnitude (U=2).
Diameter and albedo
According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Agenor measures between 50.80 and 54.38 kilometers in diameter and its surface has an albedo between 0.038 and 0.062. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0506 and a diameter of 53.89 kilometers based on an absolute magnitude of 10.2.
This minor planet was named for Agenor, who was able to inflict a wound on the Greek warrior Achilles. The Olympian deity Apollo assumed Agenor's form to distract Achilles while the Trojans forces were retreating. The minor planets 588 Achilles and 1862 Apollo are named after these two figures from Greek mythology. The body's name was suggested by Brian G. Marsden, the then director of the MPC. The official naming citation was published by the Minor Planet Center on 1 June 1975 (M.P.C. 3826).
- "1873 Agenor (1971 FH)". Minor Planet Center. Retrieved 19 June 2018.
- Schmadel, Lutz D. (2007). "(1873) Agenor". Dictionary of Minor Planet Names – (1873) Agenor. Springer Berlin Heidelberg. p. 150. doi:10.1007/978-3-540-29925-7_1874. ISBN 978-3-540-00238-3.
- "JPL Small-Body Database Browser: 1873 Agenor (1971 FH)" (2018-05-24 last obs.). Jet Propulsion Laboratory. Retrieved 19 June 2018.
- "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 19 June 2018.
- "Asteroid (1873) Agenor – 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 19 June 2018. (online catalog)
- Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 19 June 2018.
- 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 19 June 2018. (online, AcuA catalog p. 153)
- 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.
- "LCDB Data for (1873) Agenor". Asteroid Lightcurve Database (LCDB). Retrieved 19 June 2018.
- 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
- Asteroid 1873 Agenor at the Small Bodies Data Ferret
- 1873 Agenor at AstDyS-2, Asteroids—Dynamic Site
- 1873 Agenor at the JPL Small-Body Database