1404 Ajax

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1404 Ajax
001404-asteroid shape model (1404) Ajax.png
Modelled shape of Ajax from its lightcurve
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date17 August 1936
Designations
(1404) Ajax
Pronunciation/ˈeɪdʒæks/[7]
Named after
Ajax (Greek mythology)[2]
1936 QW
Minor planet category
Jupiter trojan [1][3][4]
Greek [5][6] · background [6]
Orbital characteristics [3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc81.76 yr (29,864 d)
Aphelion5.9044 AU
Perihelion4.6992 AU
5.3018 AU
Eccentricity0.1137
12.21 yr (4,459 d)
247.16°
0° 4m 50.52s / day
Inclination18.005°
332.92°
59.772°
Jupiter MOID0.0433 AU
TJupiter2.8890
Physical characteristics
Mean diameter
81.43 km (derived)[4]
81.69±3.2 km[8]
83.99±1.28 km[9]
96.34±2.25 km[10]
28.4 h[11]
29.38±0.01 h[12]
34 h[13]
0.048±0.009[9]
0.050±0.003[10]
0.0508 (derived)[4]
0.0665±0.005[8]
C (assumed)[4]
V–I = 0.960±0.032[4]
Absolute magnitude (H)
9.00[8][10]
9.3[1][3][4][9]
9.87±0.47[14]

1404 Ajax /ˈeɪdʒæks/ is a carbonaceous Jupiter trojan from the Greek camp, approximately 83 kilometers (52 miles) kilometers in diameter. It was discovered on 17 August 1936, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany, and named after the legendary warrior Ajax from Greek mythology.[1] The assumed C-type asteroid belongs to the 40 largest Jupiter trojans and has a longer than average rotation period of 29.4 hours.[4]

Orbit and classification[]

Ajax is a C-type asteroid, that orbits in the leading Greek camp at Jupiter's L4 Lagrangian point, 60° ahead of its orbit (see Trojans in astronomy). It is also a non-family asteroid in the Jovian background population.[6][15] Jupiter trojans are thought to have been captured into their orbits during or shortly after the early stages of the formation of the Solar System. More than 4,500 Jupiter trojans in the Greek camp and 7,000 in total have been discovered.[5]

It orbits the Sun at a distance of 4.7–5.9 AU once every 12 years and 3 months (4,459 days; semi-major axis of 5.3 AU). Its orbit has an eccentricity of 0.11 and an inclination of 18° with respect to the ecliptic.[3] The body's observation arc begins at Heidelberg 6 days after its official discovery observations in August 1936.[1]

Physical characteristics[]

Ajax is an assumed, carbonaceous C-type asteroid, while its V–I color index of 0.96 agrees with most D-type asteroids, which is the dominant spectral type among the large Jupiter trojans.[4]

Rotation period[]

In December 2010, a rotational lightcurve of Ajax was obtained from photometric observations taken by Robert Stephens at the Goat Mountain Astronomical Research Station (G79) in California. Lightcurve analysis gave a rotation period of 29.38 hours with a brightness variation of 0.30 magnitude (U=3-),[12] superseding fragmentary photometric measurements by Richard P. Binzel (1988), and by Roberto Crippa and Federico Manzini (2009) at the Sozzago Astronomical Station (A12), which gave a period of 28.4 and 34 hours, respectively (U=1/2-).[4][11][13]

Diameter and albedo[]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ajax measures between 81.69 and 96.34 kilometers in diameter and its surface has an albedo between 0.048 and 0.0665.[8][9][10] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0508 and a diameter of 81.43 kilometers based on an absolute magnitude of 9.3.[4]

100+ largest Jupiter trojans

Naming[]

This minor planet was named for Ajax the Great, a Greek warrior of great strength and courage in the Trojan War. He is the half brother of Teucer and son of king Telamon, who kills himself because Achilles' armor was awarded to Odysseus. The Jupiter trojans 588 Achilles, 1143 Odysseus and 1749 Telamon and 2797 Teucer are all named after these figures from Greek mythology.[2] The official naming of Ajax was first cited in The Names of the Minor Planets by Paul Herget in 1955 (H 127).[2]

References[]

  1. ^ Jump up to: a b c d e "1404 Ajax (1936 QW)". Minor Planet Center. Retrieved 13 June 2018.
  2. ^ Jump up to: a b c Schmadel, Lutz D. (2007). "(1404) Ajax". Dictionary of Minor Planet Names – (1404) Ajax. Springer Berlin Heidelberg. p. 113. doi:10.1007/978-3-540-29925-7_1405. ISBN 978-3-540-00238-3.
  3. ^ Jump up to: a b c d "JPL Small-Body Database Browser: 1404 Ajax (1936 QW)" (2018-05-23 last obs.). Jet Propulsion Laboratory. Retrieved 13 June 2018.
  4. ^ Jump up to: a b c d e f g h i j "LCDB Data for (1404) Ajax". Asteroid Lightcurve Database (LCDB). Retrieved 13 June 2018.
  5. ^ Jump up to: a b "List of Jupiter Trojans". Minor Planet Center. 30 May 2018. Retrieved 13 June 2018.
  6. ^ Jump up to: a b c "Asteroid (1404) Ajax – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 June 2018.
  7. ^ 'Polydamas' in Noah Webster (1884) A Practical Dictionary of the English Language
  8. ^ Jump up to: a b c d 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 15 June 2018.
  9. ^ Jump up to: 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)
  10. ^ Jump up to: 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)
  11. ^ Jump up to: a b Binzel, Richard P.; Sauter, Linda M. (February 1992). "Trojan, Hilda, and Cybele asteroids – New lightcurve observations and analysis". Icarus. 95 (2): 222–238. Bibcode:1992Icar...95..222B. doi:10.1016/0019-1035(92)90039-A. ISSN 0019-1035. Retrieved 11 January 2017.
  12. ^ Jump up to: a b French, Linda M.; Stephens, Robert D.; Lederer, Susan M.; Coley, Daniel R.; Rohl, Derrick A. (April 2011). "Preliminary Results from a Study of Trojan Asteroids". The Minor Planet Bulletin. 38 (2): 116–120. Bibcode:2011MPBu...38..116F. ISSN 1052-8091. Retrieved 11 January 2017.
  13. ^ Jump up to: a b Behrend, Raoul. "Asteroids and comets rotation curves – (1404) Ajax". Geneva Observatory. Retrieved 11 January 2017.
  14. ^ 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.
  15. ^ "Asteroid 1404 Ajax". Small Bodies Data Ferret. Retrieved 13 June 2018.

External links[]

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