| Discovery[1] | |
|---|---|
| Discovered by | Purple Mountain Obs. |
| Discovery site | Purple Mountain Obs. |
| Discovery date | 20 December 1965 |
| Designations | |
| (2085) Henan | |
Named after | Henan(Province of China)[2] |
| 1965 YA · 1933 RE 1938 WR · 1949 FL 1949 FP1 · 1962 CL 1963 KA · 1969 VA1 1971 BG1 · 1972 LX 1973 QX1 · 1976 GR7 | |
| main-belt · (outer) Henan[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 68.61 yr (25,060 days) |
| Aphelion | 2.9312AU |
| Perihelion | 2.4654 AU |
| 2.6983 AU | |
| Eccentricity | 0.0863 |
| 4.43yr (1,619 days) | |
| 276.34° | |
| 0° 13m 20.64s / day | |
| Inclination | 3.8343° |
| 118.14° | |
| 294.54° | |
| Physical characteristics | |
| Dimensions | 13.356±0.036 km[4] 13.67 km(calculated)[5] 13.941±0.082 km[6] 16.56±4.50 km[7] 17.61±0.32 km[8] 18 km[9]: 23 18.34±1.20 km[10] |
| 24h[11] 110±1 h[12] | |
| 0.10±0.08[7] 0.131±0.019[8] 0.145±0.020[10] 0.18(assumed)[5] 0.2510±0.0408[6] | |
| SMASS =L[1][5] L(Bus–DeMeo)[12] | |
| 11.40[6][10] · 11.55±0.48[13] · 11.60[8] · 11.8[5] · 11.9[1] · 12.12[7] | |
2085 Henan, provisional designation1965 YA, is a potentially slow rotatingasteroid and the parent body of theHenan family in the central regions of theasteroid belt, approximately 15 kilometers in diameter. It was discovered on 20 December 1965, by astronomers at thePurple Mountain Observatory in Nanking, China.[14] The asteroid was named for theHenan Province in China.[2]
Henan is theparent body of theHenan family (532),[3] a largefamily ofL-type asteroids in the intermediate main-belt, which can be further divided into four distinct families.[9]: 23
It orbits the Sun in thecentral asteroid belt at a distance of 2.5–2.9 AU once every 4 years and 5 months (1,619 days;semi-major axis of 2.70 AU). Its orbit has aneccentricity of 0.09 and aninclination of 4° with respect to theecliptic.[1]
A first observation of this asteroid was found on aprecovery, taken at theLowell Observatory in July 1906. The body'sobservation arc begins atGoethe Link Observatory in July 1943, more than 22 years prior to its official discovery observation at Purple Mountain.[14]
In the Bus–DeMeo andSMASS classification,Henan is an uncommonL-type asteroid,[1][5][12]: 5 which is also the overallspectral type for members of theHenan family.[9]: 23
As of 2017, no secure rotationallightcurve ofHenan has been obtained. In September 2004, observations byLaurent Bernasconi gave arotation period of 24 hours with a brightness variation of 0.25magnitude (U=1).[11] In February 2015, photometric observations ofHenan by an international collaboration of astronomers gave a tentative synodic period of110±1 hours and an amplitude of 0.4 magnitude, which would make it a potentiallyslow rotator (U=1).[12] An alternative period solution gave 94 hours. The latter study selectedHenan because it is a suspected "Barbarian" asteroid (named after234 Barbara) which polarimetric properties suggest that they have an unusual shape and topographic features with large concave areas.[12]
According to the surveys carried out by the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Henan measures between 13.356 and 18.34 kilometers in diameter and its surface has analbedo between 0.10 and 0.2510.[4][6][7][8][10]
TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.18 and calculates a diameter of 13.67 kilometers based on anabsolute magnitude of 11.8.[5]
Thisminor planet was named after theHenan Province in the People's Republic of China, located in the central part of the country along the lower stretch of theYellow River, which is considered the cradle of civilization in ancient China.[2] The official naming citation was published by theMinor Planet Center on 1 February 1980 (M.P.C. 5184).[15]
