1404 Ajax

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1404 Ajax
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 17 August 1936
Designations
MPC designation (1404) Ajax
Pronunciation /ˈæks/ · AY-jaks
Named after
Ajax (Greek mythology)[2]
1936 QW
Jupiter trojan[1][3][4]
Greek[5][6] · background[6]
Orbital characteristics[3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc 81.76 yr (29,864 d)
Aphelion 5.9044 AU
Perihelion 4.6992 AU
5.3018 AU
Eccentricity 0.1137
12.21 yr (4,459 d)
247.16°
0° 4m 50.52s / day
Inclination 18.005°
332.92°
59.772°
Jupiter MOID 0.0433 AU
TJupiter 2.8890
Physical characteristics
Mean diameter
81.43 km (derived)[4]
81.69±3.2 km[7]
83.99±1.28 km[8]
96.34±2.25 km[9]
28.4 h[10]
29.38±0.01 h[11]
34 h[12]
0.048±0.009[8]
0.050±0.003[9]
0.0508 (derived)[4]
0.0665±0.005[7]
C (assumed)[4]
V–I = 0.960±0.032[4]
9.00[7][9]
9.3[1][3][4][8]
9.87±0.47[13]

1404 Ajax (/ˈæks/ AY-jaks), provisional designation 1936 QW, 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[edit]

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][14] 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[edit]

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[edit]

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-),[11] 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][10][12]

Diameter and albedo[edit]

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.[7][8][9] 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]

List of largest Jupiter Trojans above 50 km
#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
 
Largest Jupiter Trojans by survey(A)
(mean-diameter in kilometers; YoD: Year of Discovery)
Designation WISE IRAS Akari Ln RP V–I YoD Ref
624 Hektor 225 233 230.99 L4 6.92 0.930 1907 list
617 Patroclus 140.362 140.92 140.85 L5 102.80 0.830 1906 list
911 Agamemnon 131.038 166.66 185.30 L4 6.59 0.980 1919 list
588 Achilles 130.099 135.47 133.22 L4 7.31 0.940 1906 list
3451 Mentor 126.288 116.30 117.91 L5 7.70 0.770 1984 list
3317 Paris 118.790 116.26 120.45 L5 7.09 0.950 1984 list
1867 Deiphobus 118.220 122.67 131.31 L5 58.66 0.930 1971 list
1172 Äneas 118.020 142.82 148.66 L5 8.71 0.950 1930 list
1437 Diomedes 117.786 164.31 172.60 L4 24.49 0.810 1937 list
1143 Odysseus 114.624 125.64 130.81 L4 10.11 0.860 1930 list
2241 Alcathous 113.682 114.63 118.87 L5 7.69 0.940 1979 list
659 Nestor 112.320 108.87 107.06 L4 15.98 0.790 1908 list
3793 Leonteus 112.046 86.26 87.58 L4 5.62 0.780 1985 list
3063 Makhaon 111.655 116.14 114.34 L4 8.64 0.830 1983 list
1583 Antilochus 108.842 101.62 111.69 L4 31.54 0.950 1950 list
884 Priamus 101.093 96.29 119.99 L5 6.86 0.900 1917 list
1208 Troilus 100.477 103.34 111.36 L5 56.17 0.740 1931 list
1173 Anchises 99.549 126.27 120.49 L5 11.60 0.780 1930 list
2207 Antenor 97.658 85.11 91.32 L5 7.97 0.950 1977 list
2363 Cebriones 95.976 81.84 84.61 L5 20.05 0.910 1977 list
4063 Euforbo 95.619 102.46 106.38 L4 8.85 0.950 1989 list
2357 Phereclos 94.625 94.90 98.45 L5 14.39 0.960 1981 list
4709 Ennomos 91.433 80.85 80.03 L5 12.28 0.690 1988 list
2797 Teucer 89.430 111.14 113.99 L4 10.15 0.920 1981 list
2920 Automedon 88.574 111.01 113.11 L4 10.21 0.950 1981 list
(15436) 1998 VU30 87.646 85.71 78.63 L4 8.97 0.870 1998 list
3596 Meriones 87.380 75.09 73.28 L4 12.96 0.830 1985 list
2893 Peiroos 86.884 87.46 86.76 L5 8.96 0.950 1975 list
4086 Podalirius 85.495 86.89 85.98 L4 10.43 0.870 1985 list
4060 Deipylos 84.043 79.21 86.79 L4 9.30 0.760 1987 list
1404 Ajax 83.990 81.69 96.34 L4 29.38 0.960 1936 list
4348 Poulydamas 82.032 70.08 87.51 L5 9.91 0.840 1988 list
5144 Achates 80.958 91.91 89.85 L5 5.96 0.920 1991 list
4833 Meges 80.165 87.33 89.39 L4 14.25 0.940 1989 list
2223 Sarpedon 77.480 94.63 108.21 L5 22.74 0.880 1977 list
(4489) 1988 AK 76.595 92.93 95.02 L4 12.58 0.950 1988 list
2260 Neoptolemus 76.435 71.65 81.28 L4 8.18 0.950 1975 list
5254 Ulysses 76.147 78.34 80.00 L4 28.72 0.970 1986 list
(3708) 1974 FV1 75.661 79.59 76.75 L5 6.55 0.980 1974 list
2674 Pandarus 74.267 98.10 101.72 L5 8.48 1.000 1982 list
3564 Talthybius 73.730 68.92 74.11 L4 40.59 0.900 1985 list
4834 Thoas 72.331 86.82 96.21 L4 18.19 0.950 1989 list
(7641) 1986 TT6 71.839 68.97 75.28 L4 27.77 0.980 1986 list
3540 Protesilaos 70.225 76.84 87.66 L4 8.95 0.940 1973 list
(11395) 1998 XN77 68.977 64.71 67.78 L4 17.38 1998 list
(4035) 1986 WD 68.733 68.23 66.99 L4 13.47 0.970 1986 list
5264 Telephus 68.472 73.26 81.38 L4 9.53 0.970 1991 list
1868 Thersites 68.163 70.08 78.89 L4 10.48 0.960 1960 list
(9799) 1996 RJ 68.033 64.87 72.42 L4 21.52 0.910 1996 list
4068 Menestheus 67.625 62.37 68.46 L4 14.40 0.950 1973 list
(23135) 2000 AN146 66.230 58.29 68.50 L4 8.69 0.860 2000 list
2456 Palamedes 65.916 91.66 99.60 L4 7.24 0.920 1966 list
3709 Polypoites 65.297 99.09 85.23 L4 10.04 1.000 1985 list
1749 Telamon 64.898 81.06 69.14 L4 16.98 0.970 1949 list
3548 Eurybates 63.885 72.14 68.40 L4 8.71 0.730 1973 list
4543 Phoinix 63.836 62.79 69.54 L4 38.87 1.200 1989 list
12444 Prothoon 63.835 64.31 62.41 L5 15.82 1996 list
4836 Medon 63.277 67.73 78.70 L4 9.82 0.920 1989 list
(16070) 1999 RB101 63.191 64.13 68.98 L5 20.24 0.960 1999 list
(15440) 1998 WX4 62.519 66.48 71.88 L4 21.43 0.970 1998 list
(4715) 1989 TS1 62.097 63.91 65.93 L5 8.81 0.850 1989 list
(A) Used sources: WISE/NEOWISE catalog (Grav, 2012); IRAS data (SIMPS v.6 catalog); and Akari catalog (Usui, 2011)
RP: rotation period and V–I (color index) taken from the LCDB

Note: missing data was completed with figures from the JPL SBDB (query) and from the LCDB (query form) for the
WISE/NEOWISE and SIMPS catalogs, respectively. These figures are given in italics.

Naming[edit]

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[edit]

  1. ^ a b c d e "1404 Ajax (1936 QW)". Minor Planet Center. Retrieved 13 June 2018. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1404) Ajax. Springer Berlin Heidelberg. p. 113. ISBN 978-3-540-00238-3. Retrieved 11 January 2017. 
  3. ^ 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. ^ a b c d e f g h i j "LCDB Data for (1404) Ajax". Asteroid Lightcurve Database (LCDB). Retrieved 13 June 2018. 
  5. ^ a b "List of Jupiter Trojans". Minor Planet Center. 30 May 2018. Retrieved 13 June 2018. 
  6. ^ a b c "Asteroid (1404) Ajax – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 June 2018. 
  7. ^ 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. Bibcode:2004PDSS...12.....T. Retrieved 15 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" (PDF). The Astrophysical Journal. 759 (1): 10. arXiv:1209.1549Freely accessible. Bibcode:2012ApJ...759...49G. doi:10.1088/0004-637X/759/1/49. Retrieved 13 June 2018.  (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. Retrieved 13 June 2018.  (online, AcuA catalog p. 153)
  10. ^ a b 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 11 January 2017. 
  11. ^ 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. 
  12. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1404) Ajax". Geneva Observatory. Retrieved 11 January 2017. 
  13. ^ 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" (PDF). Icarus. 261: 34–47. arXiv:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 13 June 2018. 
  14. ^ "Asteroid 1404 Ajax". Small Bodies Data Ferret. Retrieved 13 June 2018. 

External links[edit]