# 4792 Lykaon

4792 Lykaon /lɪˈkeɪɒn/ is a dark Jupiter trojan from the Trojan camp, approximately 51 kilometers (32 miles) in diameter. It was discovered on 10 September 1988, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The possibly elongated Jovian asteroid belongs to the 100 largest Jupiter trojans and has a long rotation period of 40.1 hours. It was named after the Trojan prince Lycaon from Greek mythology.

## Orbit and classification

Lykaon is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the trailering Trojan camp at the Gas Giant's L$_5$ Lagrangian point, 60° behind its orbit (see Trojans in astronomy). It is also a non-family asteroid of the Jovian background population. It orbits the Sun at a distance of 4.8–5.7 AU once every 12 years and 1 month (4,406 days; semi-major axis of 5.26 AU). Its orbit has an eccentricity of 0.09 and an inclination of 9° with respect to the ecliptic. The body's observation arc begins at Palomar with its official discovery observation in September 1988.

## Physical characteristics

In the SDSS-based taxonomy, Lykaon is a dark D-type asteroid, the most common spectral type among the larger Jupiter trojans. It has a typical V–I color index of 0.96.

### Rotation period

In April 1996, a rotational lightcurve of Lykaon was obtained from a total of six nights of photometric observations by Italian astronomer Stefano Mottola, using the Bochum 0.61-metre Telescope at La Silla Observatory in northern Chile. Lightcurve analysis gave a rotation period of 40.09±0.10 hours with a brightness variation of 0.43 magnitude (U=2+). A high brightness amplitude is indicative of a non-spherical shape. While not being a slow rotator, it has one of the longest periods among all larger Jupiter trojans (see table below).

### Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Lykaon measures 50.87 kilometers in diameter and its surface has an albedo of 0.068, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057, and calculates a diameter of 53.16 kilometers based on an absolute magnitude of 10.1. No diameter estimate for this object was published by the IRAS and Akari (satellite) surveys.
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 Dexius | 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 Dracius | 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 Socus | 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 Cteatus | 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 Iphinous | 9.8 | 68.977 | 64.71 | 67.78 | L4 | 17.38 | – | 1998 | list |
| 4035 Thestor | 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 Thronium | 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 Pheidas | 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 Charops | 9.7 | 63.191 | 64.13 | 68.98 | L5 | 20.24 | 0.960 | 1999 | list |
| 15440 Eioneus | 9.6 | 62.519 | 66.48 | 71.88 | L4 | 21.43 | 0.970 | 1998 | list |
| 4715 Medesicaste | 9.7 | 62.097 | 63.91 | 65.93 | L5 | 8.81 | 0.850 | 1989 | list |
| 34746 Thoon | 9.8 | 61.684 | 60.51 | 63.63 | L5 | 19.63 | 0.950 | 2001 | list |
| 38050 Bias | 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 Aulis | 9.4 | 59.568 | 74.53 | 81.92 | L4 | 18.48 | 0.980 | 1989 | list |
| 5648 Axius | 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 Periboea | 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 Rhoeo | 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 Leitus | 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 Hypsenor | 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. ||||||||||

## Naming

This minor planet was named by the discoverer from Greek mythology after the Trojan prince Lycaon, one of King Priam's many sons. He was captured by Achilles and sold as slave. Shortly after Lycaon returned to the Trojan War, he was slain by Achilles without mercy near the River Scamander. The official naming citation was published by the Minor Planet Center on 27 June 1991 (M.P.C. 18465).