 Orbital diagram of1992 AX | |
| Discovery[1] | |
|---|---|
| Discovered by | S. Ueda H. Kaneda |
| Discovery site | Kushiro Obs. |
| Discovery date | 4 January 1992 |
| Designations | |
| (5407) 1992 AX | |
| 1992 AX · 1987 BH2 | |
| Mars crosser[1][2][3] binary[4][5] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 66.90yr (24,434 d) |
| Aphelion | 2.3486AU |
| Perihelion | 1.3279 AU |
| 1.8383 AU | |
| Eccentricity | 0.2776 |
| 2.49 yr (910 d) | |
| 263.87° | |
| 0° 23m 43.8s / day | |
| Inclination | 11.390° |
| 117.74° | |
| 108.78° | |
| Knownsatellites | 1(D: 780 m;P: 13.52 h)[4][5] |
| Earth MOID | 0.377 AU (147LD) |
| Physical characteristics | |
| 2.78±0.55 km[6] 3.60±0.36 km[7] 3.8±0.4 km[8] 4.18±0.12 km[9] | |
| 2.5488 h[10][11] | |
| 0.199[8] 0.294[9] 0.376[7] 0.40[6] | |
| SMASS =Sk[2] · S[12] B–V =0.690[10] V–R =0.500[10] V–I =0.840[10] | |
| 13.90[7][9] 14.0[1][2] 14.47[8][10] | |
(5407) 1992 AX, provisional designation1992 AX, is a stonyasteroid and a synchronous binaryMars-crosser from the innermost region of theasteroid belt, approximately 3.6 kilometers (2.2 miles) in diameter. It was discovered on 4 January 1992, by Japanese astronomersSeiji Ueda andHiroshi Kaneda at theKushiro Observatory on Hokkaidō, Japan.[1] TheS-type asteroid has a shortrotation period of 2.5 hours.[4] Its sub-kilometersatellite was discovered in 1997.[5] As of 2018, thebinary system has not beennamed.[1]
1992 AX 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][3] It orbits the Sun at a distance of 1.3–2.3 AU once every 2 years and 6 months (910 days;semi-major axis of 1.84 AU). Its orbit has aneccentricity of 0.28 and aninclination of 11° with respect to theecliptic.[2]
The asteroid makes occasional close approaches toMars. Its next close approach, on 22 January 2027, will bring it 11,260,000 km (0.0753 AU) from Mars.[2] The body'sobservation arc begins with aprecovery taken atPalomar Observatory in November 1951, or more than 40 years prior to its official discovery observation at Kushiro.[1]
Thisminor planet wasnumbered by theMinor Planet Center on 9 December 1992 (M.P.C. 21249).[13] As of 2018, it has not beennamed.[1]
1992 AX has been characterized as a common, stonyS-type asteroid.[12] In theSMASS taxonomy, it is an Sk-subtype, that transitions between the S andK-type asteroids.[2] The body'scolor indices of 0.690 (B–V), 0.500 (V–R) and 0.840 (V–I) were also determined.[10]
Since 1997, several rotationallightcurves of1992 AX have been obtained fromphotometric observations byPetr Pravec and collaborating astronomers. Best-rated lightcurve analysis gave arotation period of 2.5488 hours with a consolidated brightness amplitude between 0.10 and 0.12magnitude (U=2/3).[4][10][11] The results supersedes a tentative period determination of 3.6 hours byMarc Buie (U=1).[4]
During the observations in January 1997, it was also revealed that1992 AX is a synchronousbinary asteroid with aminor-planet moon in its orbit.[10] The satellite measures approximately 780 meters in diameter, or about 20% of its primary, and has anorbital period of 13.52 hours with an estimated semi-major axis of 5.8 kilometers for its very circular orbit.[5] Observations by Pravec in January and February 2012 confirmed the binary nature of this asteroid, as well as its rotational and orbital periods.[4]
According to the surveys carried out by the JapaneseAkari satellite, theSpitzer Space Telescope and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE),1992 AX measures between 2.78 and 4.18 kilometers in diameter and its surface has analbedo between 0.199 and 0.40.[6][8][9]
In 2017, a study by WISE dedicated to Mars-crossing asteroids determined a diameter of 3.60 kilometers with a high albedo of 0.376.[7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.20 and derives a diameter of 3.79 kilometers based on anabsolute magnitude of 14.47.[4] The Johnston's archive gives an effective (combined) diameter of 3.98 kilometers with 3.9 and 0.78 kilometers for is primary and secondary body, respectively.[3][5]
