884 Priamus


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884 Priamus is a large Jupiter trojan from the Trojan camp, approximately 110 kilometers (68 miles) in diameter. It was discovered on 22 September 1917, by German astronomer Max Wolf at Heidelberg Observatory in southern Germany.[1] The dark D-type asteroid is one of the 20 largest Jupiter trojans and has a rotation period of 6.9 hours.[5] It was named after the Trojan king Priam from Greek mythology.[3]

884 Priamus
Discovery[1]
Discovered byM. F. Wolf
Discovery siteHeidelberg Obs.
Discovery date22 September 1917
Designations
(884) Priamus
Pronunciation[2]

Named after

Priam (Greek mythology)[3]
1917 CQ · 1929 XX
1938 KE
Jupiter trojan[1][4][5]
Trojan[6][7] · background[7]
AdjectivesPriamean
Orbital characteristics[4]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc100.54 yr (36,722 d)
Aphelion5.8147 AU
Perihelion4.5487 AU
5.1817 AU
Eccentricity0.1222
11.80 yr (4,308 d)
257.84°
0° 5m 0.96s / day
Inclination8.9150°
301.56°
335.46°
Jupiter MOID0.4171 AU
TJupiter2.9610
Physical characteristics
101.09±0.54 km[8]
119.99±2.13 km[9]
6.8605±0.0005 h[10]
0.037±0.001[9]
0.044±0.002[8]
D (Tholen)[11]
D (Pan-STARRS)[5][12]
U–B = 0.229±051[11]
B–V = 0.750±0.050[13]
V–R = 0.450±0.030[13]
V–I = 0.900±0.017[5]
8.81[1][4][5][9]
8.98[8]

Orbit and classification

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Priamus is orbiting in the trailing Trojan camp, at Jupiter's L5 Lagrangian point, 60° behind its orbit in a 1:1 resonance (also see Trojans in astronomy). It is also a non-family asteroid of the Jovian background population.[7]

It orbits the Sun at a distance of 4.5–5.8 AU once every 11 years and 10 months (4,308 days; semi-major axis of 5.18 AU). Its orbit has an eccentricity of 0.12 and an inclination of 9° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg in November 1917, two months after its official discovery observation.[1]

This minor planet was named from Greek mythology after Priam (Priamus; Priamos), the king of Troy during the Trojan War. The Jupiter trojans 624 Hektor and 3317 Paris are named after his sons Paris and Hector. The official naming of Ajax was first cited in The Names of the Minor Planets by Paul Herget in 1955 (H 86).[3]

Physical characteristics

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In the Tholen taxonomy, Priamus is a dark D-type asteroid, the most common spectral type among the Jupiter trojans, with few dozens already identified in the early Tholen and SMASS classification (Bus–Binzel).[14] Priamus has also been characterized as a D-type by Pan-STARRS' survey.[5][12]

Several rotational lightcurves have been obtained from photometric observations since the 1980s, when Priamus was first observed by William Hartmann (1988) and Stefano Mottola (1993). The best rated result from July 2010, by Robert Stephens at GMARS (G79) and Linda French at Illinois Wesleyan University using the 0.9-meter SMARTS telescope at CTIO in Chile, gave a well-defined rotation period of 6.8605±0.0005 hours with a consolidated brightness variation between 0.23 and 0.40 in magnitude (U=3).[5][10]

In January 1993 and October 2001, two lightcurves were obtained by Stefano Mottola in collaboration with Claes-Ingvar Lagerkvist and Marco Delbo at Kvistaberg and Pino Torinese observatories, respectively (U=3/2+).[15] Another measurement was made by Ukrainian astronomers in August 2010 (U=3).[16]

Between January 2015, and December 2016, photometric observations by Robert Stephens and Daniel Coley in collaboration with Brian Warner at the Center for Solar System Studies, California, gave a three concurring periods of 6.854, 6.863 and 6.865 hours (U=3/3/3).[17][18][19][a]

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Priamus measures 101.09 and 119.99 kilometers in diameter and its surface has an albedo of 0.044 and 0.037, respectively.[8][9] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 96.29 kilometers based on an absolute magnitude of 8.81.[5]

  1. ^ Lightcurve plots of (884) Priamus from Jan 2015, Jan 2016 and Dec 2016 by Daniel Coley and Robert Stephens at the Center for Solar System Studies (U80) and (U81). Quality code is 3/3/3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3.
  1. ^ a b c d e "884 Priamus (1917 CQ)". Minor Planet Center. Retrieved 13 June 2018.
  2. ^ Noah Webster (1884) A Practical Dictionary of the English Language
  3. ^ a b c Schmadel, Lutz D. (2007). "(884) Priamus". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 80. doi:10.1007/978-3-540-29925-7_885. ISBN 978-3-540-00238-3.
  4. ^ a b c d "JPL Small-Body Database Browser: 884 Priamus (1917 CQ)" (2018-05-24 last obs.). Jet Propulsion Laboratory. Retrieved 13 June 2018.
  5. ^ a b c d e f g h "LCDB Data for (884) Priamus". Asteroid Lightcurve Database (LCDB). Retrieved 18 August 2016.
  6. ^ "List of Jupiter Trojans". Minor Planet Center. 30 May 2018. Retrieved 13 June 2018.
  7. ^ a b c "Asteroid (884) Priamus – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 June 2018.
  8. ^ a b c d 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. S2CID 119101711. (online catalog)
  9. ^ a b c d 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. (online, AcuA catalog p. 153)
  10. ^ a b French, Linda M.; Stephens, Robert D.; Lederer, Susan M.; Rohl, Derrick A. (January 2011). "The Lightcurve of Jovian Trojan Asteroid 884 Priamus". The Minor Planet Bulletin. 38 (1): 2–3. Bibcode:2011MPBu...38....2F. ISSN 1052-8091. Retrieved 13 June 2018.
  11. ^ a b "Asteroid 884 Priamus". Small Bodies Data Ferret. Retrieved 13 June 2018.
  12. ^ a b 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. S2CID 53493339.
  13. ^ a b 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.
  14. ^ "JPL Small-Body Database Search Engine: [ spec. type = D (Tholen) or type = D (SMASSII) ]". JPL Solar System Dynamics. Retrieved 18 August 2016.
  15. ^ 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.
  16. ^ Shevchenko, V. G.; Belskaya, I. N.; Slyusarev, I. G.; Krugly, Yu. N.; Chiorny, V. G.; Gaftonyuk, N. M.; et al. (January 2012). "Opposition effect of Trojan asteroids". Icarus. 217 (1): 202–208. Bibcode:2012Icar..217..202S. doi:10.1016/j.icarus.2011.11.001. Retrieved 13 June 2018.
  17. ^ 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 13 June 2018.
  18. ^ Stephens, Robert D.; Coley, Daniel R.; Warner, Brian D.; French, Linda M. (October 2016). "Lightcurves of Jovian Trojan Asteroids from the Center for Solar System Studies: L4 Greek Camp and Spies". The Minor Planet Bulletin. 43 (4): 323–331. Bibcode:2016MPBu...43..323S. ISSN 1052-8091. Retrieved 13 June 2018.
  19. ^ Stephens, Robert D. (April 2017). "Lightcurve Analysis of Trojan Asteroids at the Center for Solar System Studies 2016 October - December". The Minor Planet Bulletin. 44 (2): 123–125. Bibcode:2017MPBu...44..123S. ISSN 1052-8091. PMC 7243949. PMID 32455395.