| Discovery[1] | |
|---|---|
| Discovered by | T. Smirnova |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 14 December 1971 |
| Designations | |
| (2122) Pyatiletka | |
Named after | Pyatiletka (Five-year plans of the USSR)[2] |
| 1971 XB · 1950 BE1 1950 DX · 1951 KB1 1954 DA · 1961 AL 1969 EV1 | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63.18 yr (23,075 days) |
| Aphelion | 2.4729AU |
| Perihelion | 2.3310 AU |
| 2.4019 AU | |
| Eccentricity | 0.0295 |
| 3.72yr (1,360 days) | |
| 197.74° | |
| 0° 15m 53.28s / day | |
| Inclination | 7.8981° |
| 105.50° | |
| 236.47° | |
| Physical characteristics | |
| Dimensions | 10.75 km(calculated)[3] 11.00±0.83 km[4] 11.084±0.101 km[5] 11.554±0.074 km[6] |
| 8.899±0.0053h[7] | |
| 0.1931±0.0198[6] 0.20(assumed)[3] 0.211±0.033[4] 0.224±0.023[5] | |
| S[3] | |
| 11.759±0.002(R)[7] · 12.1[1][4][6] · 12.21[3] · 12.40±0.29[8] | |
2122 Pyatiletka, provisional designation1971 XB, is a stonyasteroid from the inner regions of theasteroid belt, approximately 11 kilometers in diameter.
The asteroid was discovered on 14 December 1971 by Soviet astronomerTamara Smirnova at theCrimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula.[9] It was named for "pyatiletka", the firstFive-Year Plan of the USSR.[2]
Pyatiletka orbits the Sun in theinner main-belt at a distance of 2.3–2.5 AU once every 3 years and 9 months (1,360 days). Its orbit has aneccentricity of 0.03 and aninclination of 8° with respect to theecliptic.[1]
It was first identified as1950 BE1 atSimeiz Observatory in 1950. The body'sobservation arc begins atLowell Observatory in 1961, when it was identified as1961 AL, 10 years prior to its official discovery observation at Nauchnyj.[9]
Pyatiletka has been characterized as a stonyS-type asteroid.[3]
A fragmentary rotationallightcurve ofPyatiletka was obtained from photometric observations at thePalomar Transient Factory in California in February 2010. Lightcurve analysis gave a tentativerotation period of 8.899 hours with a brightness variation of 0.10magnitude (U=1).[7] As of 2017, no other lightcurve has been published.[3]
According to the surveys carried out by the JapaneseAkari satellite and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Pyatiletka measures between 11.00 and 11.55 kilometers in diameter, and its surface has analbedo between 0.1931 and 0.224.[4][5][6] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 10.75 kilometers with anabsolute magnitude of 12.21.[3]
Thisminor planet was named in honor of thefive-year plans of the Soviet Union on the occasion of the 50th anniversary of itsfirst adoption.[2] The official naming citation was published by theMinor Planet Center on 1 April 1980 (M.P.C. 5283).[10]
