2895 Memnon
Discovery [1] | |
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Discovered by | N. G. Thomas |
Discovery site | Anderson Mesa Stn. |
Discovery date | 10 January 1981 |
Designations | |
MPC designation | (2895) Memnon |
Pronunciation | /ˈmɛmnɒn/ MEM-non |
Named after |
Memnon [2] (Greek mythology) |
1981 AE1 · 1981 CL | |
Jupiter trojan [1][3] Trojan [4] · background [5] | |
Orbital characteristics [3] | |
Epoch 23 March 2018 (JD 2458200.5) | |
Uncertainty parameter 0 | |
Observation arc | 40.46 yr (14,779 d) |
Aphelion | 5.4989 AU |
Perihelion | 4.9823 AU |
5.2406 AU | |
Eccentricity | 0.0493 |
12.00 yr (4,382 d) | |
120.27° | |
0° 4m 55.92s / day | |
Inclination | 27.207° |
133.97° | |
277.24° | |
Jupiter MOID | 0.127 AU |
TJupiter | 2.7760 |
Physical characteristics | |
Dimensions |
km 55.67(calculated)[6] ±0.200 km 56.706[7] |
±0.010 h 7.502[8] | |
0.057 (assumed)[6] ±0.016 0.060[7] | |
C (assumed)[6] B–V = ±0.060 0.680[9] V–R = ±0.040 0.380[9] V–I = ±0.049 0.710[6] | |
9.9[7] 10.0[1][3][6] | |
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2895 Memnon (/ˈmɛmnɒn/ MEM-non), provisional designation 1981 AE1, is a dark Jupiter trojan from the Trojan camp, approximately 56 kilometers (35 miles) in diameter. It was discovered on 10 January 1981, by American astronomer Norman Thomas at Lowell's Anderson Mesa Station near Flagstaff, Arizona, in the United States.[1] The assumed C-type asteroid has a rotation period of 7.5 hours and belongs to the 80 largest Jupiter trojans. It was named after King Memnon from Greek mythology.[2]
Orbit and classification
Memnon is a Jovian asteroid located in the L5 Lagrangian point, 60° behind on Jupiter's orbit in the so-called Trojan camp .[4] It is also a non-family asteroid of the Jovian background population.[5]
It orbits the Sun at a distance of 5.0–5.5 AU once every 12 years (4,382 days; semi-major axis of 5.24 AU). Its orbit has an eccentricity of 0.05 and an inclination of 27° with respect to the ecliptic.[3] The body's observation arc begins with a precovery taken at the Australian Siding Spring Observatory in December 1977, more than 3 years prior to its official discovery observation.[1]
Physical characteristics
Memnon has been characterized as a carbonaceous C-type asteroid. Its V–I color index of 0.71 is also lower than that of most larger Jupiter trojans, which are typically D-type asteroids.[6]
Lightcurves
A first rotational lightcurve of Memnon was obtained by American astronomer Richard Binzel in the early 1980s. It gave a rotation period of 7.5 hours with a brightness variation of 0.24 magnitude (U=2).[10] In February 2005, a fragmentary lightcurve by Italian astronomer Federico Manzini at the Sozzago Astronomical Station (A12) gave a period of 7 hours (U=1).[11]
The so-far best rated lightcurve was obtained in November 1990, by Italian astronomer Stefano Mottola using the ESO 1-metre telescope at the La Silla Observatory in northern Chile. Analysis gave a period of ±0.010 hours with an amplitude of 0.22 magnitude ( 7.502U=3-).[8]
Between 2015 and 2018, photometric observations by Daniel Coley and Robert Stephens at the Center for Solar System Studies in Landers obtained several concurring periods with a brightness variation of 0.33 and 0.08, respectively (U=2/2+/2+),[12][13][14][lower-alpha 1]
Diameter and albedo
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Memnon measures 56.70 kilometers in diameter, and its surface has an albedo of 0.060,[7] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 55.67 kilometers with an absolute magnitude of 10.0.[6]
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Naming
This minor planet was named from Greek mythology after Memnon, the king of Ethiopia and nephew of King Priam of Troy. He supported the Trojan side in the Trojan War with 10,000 men and was killed in combat by the Greek hero Achilles.[2] The official naming citation was published by the Minor Planet Center on 20 December 1983 (M.P.C. 8405).[15]
Notes
- ↑ Lightcurve plots of (2895) Memnon from 2015, 2016, 2017 and 2018 by Daniel Coley and Robert Stephens at the Center for Solar System Studies: CS3-Trojan Station (U81) and DanHenge Observatory (U80), Landers. Quality code is 2+/2/3/3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3 website
References
- 1 2 3 4 5 "2895 Memnon (1981 AE1)". Minor Planet Center. Retrieved 16 June 2018.
- 1 2 3 Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (2895) Memnon. Springer Berlin Heidelberg. p. 238. ISBN 978-3-540-00238-3. Retrieved 27 December 2016.
- 1 2 3 4 "JPL Small-Body Database Browser: 2895 Memnon (1981 AE1)" (2018-05-25 last obs.). Jet Propulsion Laboratory. Retrieved 16 June 2018.
- 1 2 "List of Jupiter Trojans". Minor Planet Center. 1 June 2018. Retrieved 16 June 2018.
- 1 2 "Asteroid (2895) Memnon – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 16 June 2018.
- 1 2 3 4 5 6 7 "LCDB Data for (2895) Memnon". Asteroid Lightcurve Database (LCDB). Retrieved 16 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 16 June 2018. (online catalog)
- 1 2 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 27 December 2016.
- 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 14 June 2017.
- ↑ Binzel, Richard P.; Sauter, Linda M. (February 1992). "Trojan, Hilda, and Cybele asteroids - New lightcurve observations and analysis". Icarus: 222–238. Bibcode:1992Icar...95..222B. doi:10.1016/0019-1035(92)90039-A. ISSN 0019-1035. Retrieved 27 December 2016.
- ↑ Behrend, Raoul. "Asteroids and comets rotation curves – (2895) Memnon". Geneva Observatory. Retrieved 27 December 2016.
- ↑ 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 27 December 2016.
- ↑ 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 27 December 2016.
- ↑ Stephens, Robert D.; Coley, Daniel R. (July 2017). "Lightcurve Analysis of Trojan Asteroids at the Center for Solar System Studies 2017 January - March". The Minor Planet Bulletin. 44 (3): 252–257. Bibcode:2017MPBu...44..252S. ISSN 1052-8091. Retrieved 16 June 2018.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 16 June 2018.
External links
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- Asteroid 2895 Memnon at the Small Bodies Data Ferret
- 2895 Memnon at AstDyS-2, Asteroids—Dynamic Site
- 2895 Memnon at the JPL Small-Body Database