Astronomy:1172 Äneas

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Short description: Jupiter trojan asteroid
1172 Äneas
1172 Aneas 28.07.2014.gif
1172 Aneas orbit and position on 28 Jul 2014
Discovery[1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date17 October 1930
Designations
(1172) Äneas
Pronunciation/ɪˈnəs/[7]
Named afterAeneas (Αἰνείας Aineias)[2]
(Greek mythology)
1930 UA
Minor planet categoryJupiter trojan[1][3][4]
Trojan[5][6] · background[6]
AdjectivesÄneian
Orbital characteristics[3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc87.27 yr (31,874 d)
|{{{apsis}}}|helion}}5.7602 AU
|{{{apsis}}}|helion}}4.6762 AU
5.2182 AU
Eccentricity0.1039
Orbital period11.92 yr (4,354 d)
Mean anomaly238.45°
Mean motion0° 4m 57.72s / day
Inclination16.664°
Longitude of ascending node247.33°
50.803°
Jupiter MOID0.4772 AU
TJupiter2.9060
Physical characteristics
Mean diameter118.02±0.81 km[8]
142.82±4.8 km[9]
148.66±1.98 km[10]
Rotation period8.681±0.003 h[11][lower-alpha 1]
8.700±0.002 h[12][lower-alpha 1]
8.701±0.001 h[13][lower-alpha 1]
8.705±0.005 h[14]
8.708±0.009 h[15]
Geometric albedo0.037±0.001[10]
0.0403±0.003[9]
0.059±0.006[8]
D (Tholen)[16]
D0 (Barucci)[16]
DP (Tedesco)[16]
U–B = 0.254±0.033[16]
B–V = 0.840±0.050[17]
V–R = 0.460±0.050[17]
V–I = 0.990±0.017[4]
Absolute magnitude (H)8.08±0.13[18]
8.33[1][3][9][10][8][4]


1172 Äneas /ɪˈnəs/ is a large Jupiter trojan from the Trojan camp, approximately 140 kilometers (90 miles) in diameter. It was discovered on 17 October 1930, by astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[1] The dark D-type asteroid is one of the largest Jupiter trojans and has a rotation period of 8.7 hours.[4] It is named after the Trojan prince Aeneas, from Greek mythology.[2]

Orbit and classification

Äneas is located in the L5 Lagrangian point, 60° behind Jupiter in the so-called Trojan camp, orbiting in a 1:1 resonance (see Trojans in astronomy).[5] It is also a non-family asteroid of the Jovian background population.[6][16]

It orbits the Sun at a distance of 4.7–5.8 AU once every 11 years and 11 months (4,354 days; semi-major axis of 5.22 AU). Its orbit has an eccentricity of 0.10 and an inclination of 17° with respect to the ecliptic.[3] The body's observation arc begins with its official discovery observation at Heidelberg in October 1930.[1]

Naming

This minor planet was named after the Trojan hero Aeneas from Greek mythology. He is the son of goddess Aphrodite and Anchises after whom 1173 Anchises was named. The official naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 109).[2]

Physical characteristics

Rotation period

Several rotational lightcurves of Äneas have been obtained since the first photometric observations by William Hartmann in 1988, that gave a period of 8.33 hours, and by Stefano Mottola and Anders Erikson in 1993, using the ESO 1-metre telescope at La Silla Observatory in Chile. Lightcurve analysis gave a rotation period of 8.708±0.009 hours with a brightness variation of 0.27±0.01 magnitude ({{{1}}}).[4][15]

In July and August 2008, Susan Lederer at CTIO in Chile, and Robert Stephens at the Goat Mountain Astronomical Research Station (G79) in California, determined a well-defined period of 8.705±0.005 h with an amplitude 0.20 magnitude ({{{1}}}).[4][14] Follow-up observations during 2015–2017 by Robert Stephens and Daniel Coley at the Center for Solar System Studies gave three concurring periods of 8.701, 8.681 and 8.7 hours with an amplitude of 0.62, 0.40 and 0.21 magnitude, respectively ({{{1}}}),[11][12][13][lower-alpha 1] while in August 2011, Pierre Antonini reported a period of 11.8 hours based on a fragmentary lightcurve ({{{1}}}).[19]

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, Äneas measures between 118.02 and 148.66 kilometers in diameter – making it anywhere from the 8th to 4th largest Jupiter trojan – determined from a common absolute magnitude of 8.33 and a surface albedo between 0.037 and 0.059.[8][9][10] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0403 and a diameter of 142.82 kilometers based on an absolute magnitude of 8.33.[4]

100+ largest Jupiter trojans
Largest Jupiter Trojans by survey(A)
(mean-diameter in kilometers; YoD: Year of Discovery)
Designation H WISE IRAS Akari Ln RP V–I YoD Ref
624 Hektor 7.2 225 233 230.99 L4 6.92 0.930 1907 list
617 Patroclus 8.19 140.362 140.92 140.85 L5 102.80 0.830 1906 list
911 Agamemnon 7.89 131.038 166.66 185.30 L4 6.59 0.980 1919 list
588 Achilles 8.67 130.099 135.47 133.22 L4 7.31 0.940 1906 list
3451 Mentor 8.4 126.288 116.30 117.91 L5 7.70 0.770 1984 list
3317 Paris 8.3 118.790 116.26 120.45 L5 7.09 0.950 1984 list
1867 Deiphobus 8.3 118.220 122.67 131.31 L5 58.66 0.930 1971 list
1172 Äneas 8.33 118.020 142.82 148.66 L5 8.71 0.950 1930 list
1437 Diomedes 8.3 117.786 164.31 172.60 L4 24.49 0.810 1937 list
1143 Odysseus 7.93 114.624 125.64 130.81 L4 10.11 0.860 1930 list
2241 Alcathous 8.64 113.682 114.63 118.87 L5 7.69 0.940 1979 list
659 Nestor 8.99 112.320 108.87 107.06 L4 15.98 0.790 1908 list
3793 Leonteus 8.7 112.046 86.26 87.58 L4 5.62 0.780 1985 list
3063 Makhaon 8.4 111.655 116.14 114.34 L4 8.64 0.830 1983 list
1583 Antilochus 8.6 108.842 101.62 111.69 L4 31.54 0.950 1950 list
884 Priamus 8.81 101.093 96.29 119.99 L5 6.86 0.900 1917 list
1208 Troilus 8.99 100.477 103.34 111.36 L5 56.17 0.740 1931 list
1173 Anchises 8.89 99.549 126.27 120.49 L5 11.60 0.780 1930 list
2207 Antenor 8.89 97.658 85.11 91.32 L5 7.97 0.950 1977 list
2363 Cebriones 9.11 95.976 81.84 84.61 L5 20.05 0.910 1977 list
4063 Euforbo 8.7 95.619 102.46 106.38 L4 8.85 0.950 1989 list
2357 Phereclos 8.94 94.625 94.90 98.45 L5 14.39 0.960 1981 list
4709 Ennomos 8.5 91.433 80.85 80.03 L5 12.28 0.690 1988 list
2797 Teucer 8.7 89.430 111.14 113.99 L4 10.15 0.920 1981 list
2920 Automedon 8.8 88.574 111.01 113.11 L4 10.21 0.950 1981 list
(15436) 1998 VU30 9.1 87.646 85.71 78.63 L4 8.97 0.870 1998 list
3596 Meriones 9.2 87.380 75.09 73.28 L4 12.96 0.830 1985 list
2893 Peiroos 9.23 86.884 87.46 86.76 L5 8.96 0.950 1975 list
4086 Podalirius 9.1 85.495 86.89 85.98 L4 10.43 0.870 1985 list
4060 Deipylos 9.3 84.043 79.21 86.79 L4 9.30 0.760 1987 list
1404 Ajax 9.3 83.990 81.69 96.34 L4 29.38 0.960 1936 list
4348 Poulydamas 9.5 82.032 70.08 87.51 L5 9.91 0.840 1988 list
5144 Achates 9.0 80.958 91.91 89.85 L5 5.96 0.920 1991 list
4833 Meges 8.9 80.165 87.33 89.39 L4 14.25 0.940 1989 list
2223 Sarpedon 9.41 77.480 94.63 108.21 L5 22.74 0.880 1977 list
(4489) 1988 AK 9.0 76.595 92.93 95.02 L4 12.58 0.950 1988 list
2260 Neoptolemus 9.31 76.435 71.65 81.28 L4 8.18 0.950 1975 list
5254 Ulysses 9.2 76.147 78.34 80.00 L4 28.72 0.970 1986 list
(3708) 1974 FV1 9.3 75.661 79.59 76.75 L5 6.55 0.980 1974 list
2674 Pandarus 9.1 74.267 98.10 101.72 L5 8.48 1.000 1982 list
3564 Talthybius 9.4 73.730 68.92 74.11 L4 40.59 0.900 1985 list
4834 Thoas 9.1 72.331 86.82 96.21 L4 18.19 0.950 1989 list
(7641) 1986 TT6 9.4 71.839 68.97 75.28 L4 27.77 0.980 1986 list
3540 Protesilaos 9.3 70.225 76.84 87.66 L4 8.95 0.940 1973 list
(11395) 1998 XN77 9.8 68.977 64.71 67.78 L4 17.38 1998 list
(4035) 1986 WD 9.6 68.733 68.23 66.99 L4 13.47 0.970 1986 list
5264 Telephus 9.4 68.472 73.26 81.38 L4 9.53 0.970 1991 list
1868 Thersites 9.5 68.163 70.08 78.89 L4 10.48 0.960 1960 list
(9799) 1996 RJ 9.6 68.033 64.87 72.42 L4 21.52 0.910 1996 list
4068 Menestheus 9.5 67.625 62.37 68.46 L4 14.40 0.950 1973 list
(23135) 2000 AN146 9.9 66.230 58.29 68.50 L4 8.69 0.860 2000 list
2456 Palamedes 9.3 65.916 91.66 99.60 L4 7.24 0.920 1966 list
3709 Polypoites 9.1 65.297 99.09 85.23 L4 10.04 1.000 1985 list
1749 Telamon 9.5 64.898 81.06 69.14 L4 16.98 0.970 1949 list
3548 Eurybates 9.6 63.885 72.14 68.40 L4 8.71 0.730 1973 list
4543 Phoinix 9.7 63.836 62.79 69.54 L4 38.87 1.200 1989 list
12444 Prothoon 9.8 63.835 64.31 62.41 L5 15.82 1996 list
4836 Medon 9.5 63.277 67.73 78.70 L4 9.82 0.920 1989 list
(16070) 1999 RB101 9.7 63.191 64.13 68.98 L5 20.24 0.960 1999 list
(15440) 1998 WX4 9.6 62.519 66.48 71.88 L4 21.43 0.970 1998 list
(4715) 1989 TS1 9.7 62.097 63.91 65.93 L5 8.81 0.850 1989 list
(34746) 2001 QE91 9.8 61.684 60.51 63.63 L5 19.63 0.950 2001 list
(38050) 1998 VR38 9.8 61.603 61.04 50.44 L4 18.85 0.990 1998 list
5130 Ilioneus 9.7 60.711 59.40 52.49 L5 14.77 0.960 1989 list
5027 Androgeos 9.6 59.786 57.86 n.a. L4 11.38 0.910 1988 list
(6090) 1989 DJ 9.4 59.568 74.53 81.92 L4 18.48 0.980 1989 list
(5648) 1990 VU1 9.7 59.295 63.91 n.a. L5 37.56 0.900 1990 list
7119 Hiera 9.7 59.150 76.40 77.29 L4 400 0.950 1989 list
4805 Asteropaios 10.0 57.647 53.16 43.44 L5 12.37 1990 list
16974 Iphthime 9.8 57.341 55.43 57.15 L4 78.9 0.960 1998 list
4867 Polites 9.8 57.251 58.29 64.29 L5 11.24 1.010 1989 list
2895 Memnon 10.0 56.706 55.67 n.a. L5 7.50 0.710 1981 list
4708 Polydoros 9.9 54.964 55.67 n.a. L5 7.52 0.960 1988 list
(21601) 1998 XO89 10.0 54.909 55.67 56.08 L4 12.65 0.970 1998 list
(12929) 1999 TZ1 9.9 54.077 61.04 55.34 L5 9.27 0.880 1999 list
17492 Hippasos 10.0 53.975 55.67 n.a. L5 17.75 1991 list
5652 Amphimachus 10.1 53.921 53.16 52.48 L4 8.37 1.050 1992 list
2759 Idomeneus 9.9 53.676 61.01 52.55 L4 32.38 0.910 1980 list
(5258) 1989 AU1 10.2 53.275 50.77 n.a. L4 19.85 1.010 1989 list
(12126) 1999 RM11 10.1 53.202 n.a. n.a. L5 n.a. ? 1999 list
(15502) 1999 NV27 10.0 53.100 55.67 50.86 L5 15.13 0.875 1999 list
4754 Panthoos 10.0 53.025 53.15 56.96 L5 27.68 1977 list
4832 Palinurus 10.0 52.058 53.16 n.a. L5 5.32 1.000 1988 list
5126 Achaemenides 10.5 51.922 44.22 48.57 L4 53.02 1989 list
3240 Laocoon 10.2 51.695 50.77 n.a. L5 11.31 0.880 1978 list
4902 Thessandrus 9.8 51.263 61.04 71.79 L4 738 0.960 1989 list
11552 Boucolion 10.1 51.136 53.16 53.91 L5 32.44 1993 list
(20729) 1999 XS143 10.4 50.961 46.30 n.a. L4 5.72 1.000 1999 list
(6545) 1986 TR6 10.1 50.951 53.16 n.a. L4 16.26 0.910 1986 list
4792 Lykaon 10.1 50.870 53.16 n.a. L5 40.09 0.960 1988 list
21900 Orus 10.0 50.810 55.67 53.87 L4 13.45 0.950 1999 list
1873 Agenor 10.1 50.799 53.76 54.38 L5 20.60 1971 list
5028 Halaesus 10.2 50.770 50.77 n.a. L4 24.94 0.900 1988 list
2146 Stentor 9.9 50.755 58.29 n.a. L4 16.40 1976 list
4722 Agelaos 10.0 50.378 53.16 59.47 L5 18.44 0.910 1977 list
5284 Orsilocus 10.1 50.159 53.16 n.a. L4 10.31 0.970 1989 list
11509 Thersilochos 10.1 49.960 53.16 56.23 L5 17.37 1990 list
5285 Krethon 10.1 49.606 58.53 52.61 L4 12.04 1.090 1989 list
4791 Iphidamas 10.1 49.528 57.85 59.96 L5 9.70 1.030 1988 list
9023 Mnesthus 10.1 49.151 50.77 60.80 L5 30.66 1988 list
5283 Pyrrhus 9.7 48.356 64.58 69.93 L4 7.32 0.950 1989 list
4946 Askalaphus 10.2 48.209 52.71 66.10 L4 22.73 0.940 1988 list
(22149) 2000 WD49 10.2 48.190 50.77 50.37 L4 7.84 1.090 2000 list
(32496) 2000 WX182 10.2 48.017 50.77 51.63 L5 23.34 0.950 2000 list
5120 Bitias 10.2 47.987 50.77 n.a. L5 15.21 0.780 1988 list
12714 Alkimos 10.1 47.819 61.04 54.62 L4 28.48 1991 list
(7352) 1994 CO 9.9 47.731 55.67 47.07 L5 648 0.850 1994 list
1870 Glaukos 10.6 47.649 42.23 n.a. L5 5.99 1971 list
4138 Kalchas 10.1 46.462 53.16 61.04 L4 29.2 0.810 1973 list
(23958) 1998 VD30 10.2 46.001 50.77 47.91 L4 562 0.990 1998 list
4828 Misenus 10.4 45.954 46.30 43.22 L5 12.87 0.920 1988 list
4057 Demophon 10.1 45.683 53.16 n.a. L4 29.82 1.060 1985 list
4501 Eurypylos 10.4 45.524 46.30 n.a. L4 6.05 1989 list
4007 Euryalos 10.3 45.515 48.48 53.89 L4 6.39 1973 list
5259 Epeigeus 10.3 44.741 42.59 44.42 L4 18.42 1989 list
30705 Idaios 10.4 44.546 46.30 n.a. L5 15.74 1977 list
16560 Daitor 10.7 43.861 51.42 43.38 L5 1991 list
(15977) 1998 MA11 10.4 43.530 46.30 51.53 L5 250 0.906 1998 list
7543 Prylis 10.6 42.893 42.23 n.a. L4 17.80 1973 list
4827 Dares 10.5 42.770 44.22 n.a. L5 19.00 1988 list
1647 Menelaus 10.5 42.716 44.22 n.a. L4 17.74 0.866 1957 list
(A) Used sources: WISE/NEOWISE catalog (NEOWISE_DIAM_V1 PDS, 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. Also, listing is incomplete above #100.

Spectral type

In the Tholen and Barucci classification, Äneas is a dark D-type asteroid, while in the Tedesco classification is as D/P-type asteroid. Its high V–I color index of 0.99 is typical for D-types.[16]

Notes

  1. 1.0 1.1 1.2 1.3 Lightcurve plots of (1172) Äneas from Jan 2015, Jan 2016 and Dec 2016 (n.a.) 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.

References

  1. 1.0 1.1 1.2 1.3 1.4 "1172 Aneas (1930 UA)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1172. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(1172) Äneas". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 99. doi:10.1007/978-3-540-29925-7_1173. ISBN 978-3-540-00238-3. 
  3. 3.0 3.1 3.2 3.3 "JPL Small-Body Database Browser: 1172 Aneas (1930 UA)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001172. 
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 "LCDB Data for (1172) Äneas". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1172%7CAneas. 
  5. 5.0 5.1 "List of Jupiter Trojans". Minor Planet Center. 2 February 2018. https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html. 
  6. 6.0 6.1 6.2 "Asteroid (1172) Äneas – Proper elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?n=1172&pc=1.1.6. 
  7. "Aeneas". Merriam-Webster Dictionary. https://www.merriam-webster.com/dictionary/Aeneas. 
  8. 8.0 8.1 8.2 8.3 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. doi:10.1088/0004-637X/759/1/49. Bibcode2012ApJ...759...49G.  (online catalog)
  9. 9.0 9.1 9.2 9.3 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. Bibcode2004PDSS...12.....T. https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab. Retrieved 15 June 2018. 
  10. 10.0 10.1 10.2 10.3 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. doi:10.1093/pasj/63.5.1117. Bibcode2011PASJ...63.1117U.  (online, AcuA catalog p. 153)
  11. 11.0 11.1 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. ISSN 1052-8091. Bibcode2016MPBu...43..265S. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016MPBu...43..265S. Retrieved 3 March 2018. 
  12. 12.0 12.1 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. ISSN 1052-8091. PMID 32455395. Bibcode2017MPBu...44..123S. 
  13. 13.0 13.1 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. ISSN 1052-8091. Bibcode2015MPBu...42R.216S. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015MPBu...42R.216S. Retrieved 3 March 2018. 
  14. 14.0 14.1 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. ISSN 1052-8091. Bibcode2011MPBu...38..116F. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011MPBu...38..116F. Retrieved 3 March 2018. 
  15. 15.0 15.1 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. doi:10.1088/0004-6256/141/5/170. Bibcode2011AJ....141..170M. 
  16. 16.0 16.1 16.2 16.3 16.4 16.5 "Asteroid 1172 Äneas". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1172+Aneas. 
  17. 17.0 17.1 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. doi:10.1016/j.icarus.2016.01.026. Bibcode2016Icar..271..158C. 
  18. 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. doi:10.1016/j.icarus.2015.08.007. Bibcode2015Icar..261...34V. 
  19. Behrend, Raoul. "Asteroids and comets rotation curves – (1172) Äneas". Geneva Observatory. http://obswww.unige.ch/~behrend/page3cou.html#001172. 

External links