| Discovery[1] | |
|---|---|
| Discovered by | T. Smirnova |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 30 August 1971 |
| Designations | |
| (1857) Parchomenko | |
Named after | Praskoviya Parchomenko (Russian astronomer)[2] |
| 1971 QS1 · 1931 XT 1941 WJ · 1974 OE1 | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 85.42 yr (31,198 days) |
| Aphelion | 2.5459AU |
| Perihelion | 1.9414 AU |
| 2.2436 AU | |
| Eccentricity | 0.1347 |
| 3.36yr (1,228 days) | |
| 199.01° | |
| 0° 17m 35.88s / day | |
| Inclination | 4.4006° |
| 236.05° | |
| 174.05° | |
| Physical characteristics | |
| Dimensions | 7.986±0.201[4] 8.513±0.184 km[5] 9.84 km(calculated)[3] |
| 3.08±0.01h[6] 3.1177±0.0001 h[7] | |
| 0.20(assumed)[3] 0.2952±0.0580[5] 0.333±0.053[4] | |
| SMASS =S[1] · S[3] | |
| 12.3[5] · 12.4[1][3] | |
1857 Parchomenko, provisional designation1971 QS1, is a stonyasteroid and suspectedbinary from the inner regions of theasteroid belt, approximately 8 kilometers in diameter.
It was discovered on 30 August 1971, by Russian astronomerTamara Smirnova atCrimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula, and named after astronomerPraskoviya Parchomenko.[2][8]
Parchomenko orbits the Sun in theinner main-belt at a distance of 1.9–2.5 AU once every 3 years and 4 months (1,228 days). Its orbit has aneccentricity of 0.13 and aninclination of 4° with respect to theecliptic.[1]
First identified as1931 XT atLowell Observatory, the body's first used observation was taken atNice Observatory in 1939, extending itsobservation arc by 32 years prior to its official discovery observation at Nauchnyj.[8]
In theSMASS classification,Parchomenko is a commonS-type asteroid.[1]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Parchomenko measures 7.99 and 9.84 kilometers in diameter, and its surface has analbedo of 0.295 and 0.333, respectively.[4][5] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 8.5 kilometers, based on an absolutemagnitude of 12.4.[3]
In December 2005, a rotationallightcurve ofParchomenko was obtained from a photometric observations byRobert Stephens,Brian Warner andPetr Pravec. It gave a well-definedrotation period of 3.1177 hours with a brightness variation of 0.22 magnitude (U=3).[7]
Three possibleoccultation events were observed, suggesting thatParchomenko might be abinary asteroid, having aminor-planet moon as companion.[7] However, no new findings have been made since. In October 2008, Italian amateur astronomerSilvano Casulli measured a similar period of 3.08 hours with an amplitude of 0.27 magnitude (U=3).[6]
Thisminor planet was named in honor of Russian astronomerPraskoviya Parchomenko (1886–1970), who observed anddiscovered the minor planets1129 Neujmina and1166 Sakuntala at the CrimeanSimeiz Observatory during the 1930s and 1940s.[2] The officialnaming citation was published by theMinor Planet Center on 1 June 1975 (M.P.C. 3826).[9]
