| Discovery [1] | |
|---|---|
| Discovered by | R. H. McNaught |
| Discovery site | Siding Spring Obs. |
| Discovery date | 9 October 1990 |
| Designations | |
| (5682) Beresford | |
Named after | Tony Beresford [1] (Australian amateur astronomer) |
| 1990 TB · 1969 PP 1983 RV5 | |
| Mars crosser [1][2][3] | |
| Orbital characteristics [2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 68.89yr (25,163 d) |
| Aphelion | 2.9826AU |
| Perihelion | 1.6114 AU |
| 2.2970 AU | |
| Eccentricity | 0.2985 |
| 3.48 yr (1,272 d) | |
| 77.335° | |
| 0° 16m 59.16s / day | |
| Inclination | 7.9606° |
| 212.78° | |
| 138.58° | |
| Earth MOID | 0.616 AU (240LD) |
| Physical characteristics | |
| 4.125±0.661 km[4][5] 5.66 km(calculated)[3] 7.33±0.73 km[6] | |
| 3.769±0.005 h[a] | |
| 0.109[6] 0.20(assumed)[3] 0.365±0.145[4][5] | |
| S(assumed)[3] | |
| 13.60[2][3][5][4] 13.70[1][6] | |
5682 Beresford, provisional designation1990 TB is a stonyasteroid and sizableMars-crosser from the inner regions of theasteroid belt, approximately 6 kilometers (3.7 miles) in diameter. It was discovered on 9 October 1990, by astronomerRobert McNaught at theSiding Spring Observatory in Australia.[1] The assumedS-type asteroid has a shortrotation period of 3.8 hours.[3] It was named after Australian amateur astronomerAnthony Beresford.[1]
Beresford is a member of theMars-crossing asteroids, a dynamically unstablegroup between themain belt and thenear-Earth populations, crossing the orbit ofMars at 1.66 AU.[1] It orbits the Sun at a distance of 1.61–2.98 AU once every 3 years and 6 months (1,272 days;semi-major axis of 2.3 AU). Its orbit has aneccentricity of 0.30 and aninclination of 8° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery taken atPalomar Observatory in November 1949, or almost 41 years prior to its official discovery observation atSiding Spring in October 1990.[1]
Thisminor planet was named after Tony Beresford (Anthony Charles Beresford; born 1942), an Australianamateur astronomer who has been an active observer ofartificial satellites as part of theOperation Moonwatch program. He has also been instrumental in the distribution of astronomical information and discoveries in South Australia.[1] The name was suggested byDuncan I. Steel and theofficial citation was published by theMinor Planet Center on 2 April 1999 (M.P.C. 34341).[7]
Beresford is an assumed, stonyS-type asteroid,[3] the most commonspectral type in the inner region of theSolar System.
In October 2011, a rotationallightcurve ofBeresford was obtained fromphotometric observations byBrian Skiff. Lightcurve analysis gave arotation period of3.769±0.005 hours with a brightness variation of0.08±0.01magnitude (U=3-), indicative of a spherical shape.[a] The result supersedes an alternative period solution of7.536±0.002 hours (twice the period) with an amplitude of0.20 magnitude previously obtained by Robert A. Koff at the Antelope Hills Observatory (H09) in Colorado in October 2004 (U=2).[8][b]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Beresford measures 4.13 kilometers in diameter and its surface has analbedo of 0.36(5).[5][4] However, a 2017-WISE-study dedicated to Mars-crossing asteroids determined a larger diameter of 7.33 kilometers due to a much lower albedo of 0.109.[6] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for as stony asteroid of 0.20 and derives a diameter of 5.66 kilometers based on anabsolute magnitude of 13.6.[3]
With a diameter of up to 7.3 kilometers,Beresford is still one of the smaller "sizable"Mars-crossing asteroids (5–15 km). These include3581 Alvarez (13.69 km)1065 Amundsenia (9.75 km),1139 Atami (9.35 km),3737 Beckman (14.36 km),1474 Beira (15.46 km),1011 Laodamia (7.39 km),1727 Mette (5.44 km),1131 Porzia (7.13 km),1235 Schorria (5.55 km),985 Rosina (8.18 km),1310 Villigera (15.24 km), and1468 Zomba (7 km), which are smaller than the largest members of this dynamical group, namely,132 Aethra,323 Brucia (former Mars-crosser),1508 Kemi,2204 Lyyli and512 Taurinensis, all larger than 20 kilometers.
