# 4543 Phoinix

4543 Phoinix is a large Jupiter trojan from the Greek camp, approximately 63 kilometers (39 miles) in diameter. It was discovered on 2 February 1989, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California. The assumed C-type asteroid is possibly elongated and has a longer-than-average rotation period of 38.9 hours. It is one of the 60 largest Jupiter trojans and was named after Phoenix (Phoinix) from Greek mythology.

## Orbit and classification

Phoinix is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's L$_4$ Lagrangian point, 60° ahead of the Gas Giant's orbit in a 1:1 resonance (see Trojans in astronomy). This asteroid is not a member of any asteroid family but belongs to the Jovian background population.
It orbits the Sun at a distance of 4.6–5.6 AU once every 11 years and 7 months (4,237 days; semi-major axis of 5.12 AU). Its orbit has an eccentricity of 0.10 and an inclination of 15° with respect to the ecliptic.
The asteroid was first observer as 1930 DN at Heidelberg Observatory in February 1930. The body's observation arc begins with a precovery taken at Palomar in April 1955, nearly 34 years prior to its official discovery observation.

## Physical characteristics

Phoinix is a generically assumed C-type asteroid. Its V–I color index of 1.20 is the highest of all larger Jovian trojans, which are typically D-types with a V–I index near 0.90 (also see table below).

### Rotation period

In November 2011, a rotational lightcurve of Phoinix was obtained from photometric observations by Italian astronomer Albino Carbognani at the OAVdA Observatory (B04), Italy, with follow-up observations conducted at Calar Alto Observatory by Stefano Mottola and Uri Carsenty the following month. Lightcurve analysis gave a rotation period of 38.866 hours with a brightness amplitude of at least 0.34 magnitude (U=2+). While not being a slow rotator, Phoinix has a longer-than average period, especially for a large Jupiter trojan. Its relatively high brightness amplitude is indicative of a non-spherical, elongated shape.

### Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, and the Infrared Astronomical Satellite IRAS, Phoinix measures between 62.79 and 69.54 kilometers in diameter and its surface has an albedo between 0.049 and 0.059.
The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0540 and a diameter of 62.73 kilometers based on an absolute magnitude of 9.8.
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 Phoenix (Phoinix), a wise Greek leader in the Trojan War, who raised Achilles and convinced him to join the campaign. The official naming citation was published by the Minor Planet Center on 28 April 1991 (M.P.C. 18143).