4722 Agelaos
Discovery [1] | |
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Discovered by |
C. J. van Houten I. van Houten-G. T. Gehrels |
Discovery site | Palomar Obs. |
Discovery date | 16 October 1977 |
Designations | |
MPC designation | (4722) Agelaos |
Pronunciation |
/ˌædʒɪˈleɪəs/ AJ-i-LAY-əs |
Named after |
Agelaus [1] (Greek mythology) |
4271 T-3 · 1988 TZ2 | |
Jupiter trojan [1][2] Trojan [3] · background [4] | |
Orbital characteristics [2] | |
Epoch 23 March 2018 (JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 40.61 yr (14,834 d) |
Aphelion | 5.7858 AU |
Perihelion | 4.6298 AU |
5.2078 AU | |
Eccentricity | 0.1110 |
11.88 yr (4,341 d) | |
141.35° | |
0° 4m 58.44s / day | |
Inclination | 8.8147° |
64.985° | |
315.72° | |
Jupiter MOID | 0.2425 AU |
TJupiter | 2.9640 |
Physical characteristics | |
Mean diameter |
±0.34 km 50.38[5] ±4.39 km 59.47[6] |
±0.014 h 18.438[7][lower-alpha 1] | |
±0.010 0.067[6] ±0.012 0.076[5] | |
C (assumed)[8] B–V = ±0.060 0.690[9] V–R = ±0.040 0.500[9] V–I = ±0.046 0.910[8] | |
9.70[6] 9.9[5] 10.0[1][2] | |
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4722 Agelaos, provisional designation 4271 T-3, is a Jupiter trojan from the Trojan camp, approximately 53 kilometers (33 miles) in diameter. It was discovered during the third Palomar–Leiden Trojan survey at the Palomar Observatory in California in 1977.[1] The Jovian asteroid has a rotation period of 18.4 hours and belongs to the 90 largest Jupiter trojans.[8] It was named after Agelaus from Greek mythology.[1]
Discovery
Agelaos was discovered on 16 October 1977, by Dutch astronomer couple Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at the Palomar Observatory in California. The body's observation arc begins with its first observations at Palomar on 7 October 1977, just nine day prior to its official discovery observation.[1]
Palomar–Leiden survey
The survey designation "T-3" stands for the third Palomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar and Leiden Observatory in the 1960s and 1970s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Ingrid and Cornelis van Houten at Leiden Observatory where astrometry was carried out. The trio are credited with the discovery of several thousand asteroid discoveries.[10]
Orbit and classification
Agelaos 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 .[3] It is also a non-family asteroid of the Jovian background population.[4]
It orbits the Sun at a distance of 4.6–5.8 AU once every 11 years and 11 months (4,341 days; semi-major axis of 5.21 AU). Its orbit has an eccentricity of 0.11 and an inclination of 9° with respect to the ecliptic.[2]
Physical characteristics
Agelaos is an assumed, carbonaceous C-type asteroid. It has a V–I color index of 0.91, typical for most Jovian D-type asteroids, the dominant spectral type among the larger Jupiter trojans.[8]
Rotation period
In December 2002, a first rotational lightcurve of Agelaos was obtained from photometric observations over two consecutive nights by Italian astronomer Stefano Mottola with the 1.2-meter telescope at Calar Alto Observatory in Spain. Lightcurve analysis gave a rotation period of 18.61 hours with a brightness amplitude of 0.23 magnitude (U=2).[11] Observations in the R-band by astronomers at the Palomar Transient Factory in October 2012 gave a period of 18.456 hours with an amplitude of 0.15 magnitude (U=2).[8][12]
The so-far best-rated lightcurve by Robert Stephens at the Center for Solar System Studies in Landers, California, gave a concurring period of ±0.014 and a brightness variation of 0.19 ( 18.438U=2).[7][8][lower-alpha 1]
Diameter and albedo
According to the surveys carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer and the Japanese Akari satellite, Agelaos measures 50.38 and 59.47 kilometers in diameter and its surface has an albedo of 0.076 and 0.067, respectively.[5][6] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 53.16 kilometers based on an absolute magnitude of 10.1.[8]
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Naming
This minor planet was named from Greek mythology after the shepherd Agelaus, who was ordered by King Priam to expose the Trojan prince Paris as an infant – because the prophecy predicted that he would cause the destruction of Troy– but brought him up as his own son instead. The official naming citation was published by the Minor Planet Center on 28 May 1991 (M.P.C. 18308).[13]
Notes
References
- 1 2 3 4 5 6 7 "4722 Agelaos (4271 T-3)". Minor Planet Center. Retrieved 19 June 2018.
- 1 2 3 4 "JPL Small-Body Database Browser: 4722 Agelaos (4271 T-3)" (2018-05-19 last obs.). Jet Propulsion Laboratory. Retrieved 19 June 2018.
- 1 2 "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 19 June 2018.
- 1 2 "Asteroid (4722) Agelaos – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 19 June 2018.
- 1 2 3 4 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)
- 1 2 3 4 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)
- 1 2 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 19 June 2018.
- 1 2 3 4 5 6 7 "LCDB Data for (4722) Agelaos". Asteroid Lightcurve Database (LCDB). Retrieved 19 June 2018.
- 1 2 Chatelain, Joseph P.; Henry, Todd J.; French, Linda M.; Winters, Jennifer G.; Trilling, David E. (June 2016). "Photometric colors of the brightest members of the Jupiter L5 Trojan cloud". Icarus. 271: 158–169. Bibcode:2016Icar..271..158C. doi:10.1016/j.icarus.2016.01.026. Retrieved 13 June 2016.
- ↑ "Minor Planet Discoverers (by number)". Minor Planet Center. 31 May 2018. Retrieved 19 June 2018.
- ↑ 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 19 June 2018.
- ↑ 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" (PDF). The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 19 June 2018.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 June 2018.
External links
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- Asteroid 4722 Agelaos at the Small Bodies Data Ferret
- 4722 Agelaos at AstDyS-2, Asteroids—Dynamic Site
- 4722 Agelaos at the JPL Small-Body Database