 Radar image of the2005 UP156 binary system taken by theArecibo Observatory in June 2017 | |
| Discovery[1] | |
|---|---|
| Discovered by | Spacewatch |
| Discovery site | Kitt Peak National Obs. |
| Discovery date | 31 October 2005 |
| Designations | |
| (190166)2005 UP156 | |
| 2005 UP156 | |
| NEO · Amor[1][2] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 14.80 yr (5,405 days) |
| Aphelion | 3.1090AU |
| Perihelion | 1.1221 AU |
| 2.1155 AU | |
| Eccentricity | 0.4696 |
| 3.08yr (1,124 days) | |
| 18.539° | |
| 0° 19m 13.08s / day | |
| Inclination | 4.2083° |
| 193.41° | |
| 91.156° | |
| Knownsatellites | 1[3][4][5] |
| Earth MOID | 0.1316 AU (51.3LD) |
| Physical characteristics | |
| 1.045±0.025 km[6] 1.08 km(calculated)[3] | |
Meandensity | 1.8 g/cm3[7] |
| 40.5±0.1 h[8][a] 40.542±0.003 h[4] 40.572±0.003 h[a][b] 40.6±0.5 h[7] | |
| 0.20(assumed)[3] 0.234±0.033[6] | |
| S[3] | |
| 17.1[1][6] 17.2[3] | |
(190166) 2005 UP156 is a stonyasteroid andbinary system, classified asnear-Earth object of theApollo group, approximately 1 kilometer in diameter. It was discovered on 31 October 2005, by astronomers of theSpacewatch survey at theKitt Peak National Observatory in Arizona, United States.[2] Itsminor-planet moon with an orbital period of 40.25 hours was discovered in 2017.[4]
2005 UP156 is anAmor asteroid that approaches the orbit of Earth from beyond but does not cross it. It orbits the Sun at a distance of 1.1–3.1 AU once every 3 years and 1 month (1,124 days). Its orbit has aneccentricity of 0.47 and aninclination of 4° with respect to theecliptic.[1] The body'sobservation arc begins with aprecovery image taken byNEAT atPalomar Observatory in November 2002, almost four years prior to its official discovery observation.[2] Due to its high eccentricity, the asteroid is also aMars-crosser, which means that it also crosses the orbit of Mars (at 1.666 AU).
Thisnear-Earth object has anEarthminimum orbital intersection distance of 0.1316 AU (19,700,000 km) which corresponds to 51.3lunar distances. On 10 July 2017, it approached Earth to a distance of 0.133 AU and will make its next close approach at 0.128 AU in July 2057.[1]
2005 UP156 is an assumedS-type asteroid.[3]
Since 2004, several rotationallightcurves of2005 UP156 were obtained from photometric observations by French amateur astronomersDavid Romeuf,René Roy, as well as by American astronomerBrian Warner. Analysis of the best-rated lightcurve gave arotation period of 40.542 hours with a brightness variation of 1.1magnitude (U=2/3/3/2).[8][4][7][a][b]
While not being aslow rotator,2005 UP156 has a much longer rotation period than most asteroids, especially for it nearly sub-kilometer size. The lightcurve's high brightness amplitude also indicates that the body has a non-spheroidal shape.
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,2005 UP156 measures 1.045 kilometers in diameter and its surface has analbedo of 0.234,[6] while theCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.08 kilometers based on anabsolute magnitude of 17.2.[3] The asteroid has an estimated density of 1.8 g/cm3.[7]
In May 2017,photometric observations by Brian Warner and Alan Harris revealed that2005 UP156 is a synchronousbinary system with asecondary component orbiting around the systembarycenter every 40.572 hours.[4][b] The secondary has been confirmed by radar observations.[5]
Thisminor planet wasnumbered by theMinor Planet Center on 19 August 2008.[9] As of 2018, it has not beennamed.[2]
