| Discovery[1] | |
|---|---|
| Discovered by | N. Chernykh |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 22 September 1973 |
| Designations | |
| (2006) Polonskaya | |
Named after | Elena Polonskaïa (Russian astronomer)[2] |
| 1973 SB3 · 1941 SD 1948 QH · 1966 VC | |
| main-belt · Flora[3] | |
| Orbital characteristics[4] | |
| Epoch 17 December 2020 (JD 2459200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 70.93yr (25,909 d) |
| Aphelion | 2.7721AU |
| Perihelion | 1.8777 AU |
| 2.3249 AU | |
| Eccentricity | 0.1923 |
| 3.55 yr (1,295 d) | |
| 107.39° | |
| 0° 16m 40.8s / day | |
| Inclination | 4.9106° |
| 0.8717° | |
| 24.849° | |
| Knownsatellites | 1[5][6][7] |
| Physical characteristics | |
| 4.625±0.163 km[8][9] 4.804 km[5][10] | |
Meandensity | 1.6 g/cm3(est.)[6] |
| 3.1183 h[11] | |
| 0.3498[10] 0.354±0.096[8][9] | |
| S(family-based)[5] | |
| 13.08[1][4] | |
| Discovery[6][7] | |
|---|---|
| Discovered by | D. Pray,P. Pravec,P. Kušnirák,W. Cooney,J. Gross, and D. Terrell |
| Discovery date | 1 November 2005 |
| Light curve | |
| Orbital characteristics | |
| 8.5 km | |
| 0.7979±0.0008 d (19 hours, 9 ± 1 minutes) | |
| 13 mas (maximum) | |
| Satellite of | 2006 Polonskaya |
| Physical characteristics | |
| 0.99 km | |
| Volume | 0.5 km3(est.) |
| 6.6571±0.0002 h | |
| <3.3 fainter than primary | |
| 18.1 | |
2006 Polonskaya (provisional designation:1973 SB3) is a stonyFlora asteroid and asynchronousbinary system from the inner regions of theasteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered on 22 September 1973, by Soviet astronomerNikolai Chernykh at theCrimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula, and later named after Ukrainian astronomerElena Kazimirtchak-Polonskaïa.[1][2] Its one-kilometer-sizedsatellite was discovered by an international collaboration of astronomers in November 2005.[6][7]
Polonskaya is a member of theFlora family, one of the largest collisional populations ofstony asteroids, when applying the synthetichierarchical clustering method (HCM) byNesvorný.[3] However, according to another HCM-analysis byMilani andKnežević (AstDys), it is abackground asteroid as in this analysis the Floraasteroid clan is not recognized.[12] Polonskaya orbits the Sun in theinner main-belt at a distance of 1.9–2.8 AU once every 3 years and 7 months (1,295 days;semi-major axis of 2.32 AU). Its orbit has aneccentricity of 0.19 and aninclination of 5° with respect to theecliptic.[4] On 16 September 1941, it was first observed at the FinnishTurku Observatory in Finland. The body'sobservation arc begins in April 1950 atPalomar Mountain, about 23 years prior to its official discovery observation.[1]
Thisminor planet was named after Russian astronomer Elena Ivanovna Kazimirchak-Polonskaya (1902–1992), who researched the motion and orbital evolution ofcomets, in particular the capture of comets by major planets. She was a member ofIAU's Commission XX, and was awarded theF. A. Bredikhin prize.[2] The officialnaming citation was published by theMinor Planet Center on 1 September 1978 (M.P.C. 4481).[13]
In 2005, it was claimed thatlightcurve observations indicate that Polonskaya has a smallmoon about 0.99 km in diameter.[6] However, the non-synchronously rotating binary still needs to be fully resolved in order to confirm such satellite. Alternatively, the presence of another body has also been suggested to explain the lightcurve's irregular period, which would make it atriple asteroid.[7]
Polonskaya is considered a stonyS-type asteroid with a typically highalbedo due to its membership to theFlora family.[3]
Between 2005 and 2010, several rotationallightcurves of Polonskaya were obtained fromphotometric observations byDonald Pray,Petr Pravec,Peter Kušnirák,Walter Cooney,John Gross and Dirk Terrell. Lightcurve analysis gave arotation period between 3.114 and 3.1183 hours with a brightness amplitude of 0.18–0.10magnitude for the best rated results (U=3/3/3/3).[11][14] A later retracted alternative period solution of6.69±0.01 h (about twice as long) has also been proposed.[15] In September 2019, follow-up observations by Pravec gave an unchanged rotation period of3.1181±0.0005 h (U=3).[5]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, Polonskaya measures 4.625 kilometers in diameter and its surface has an albedo of 0.354.[8][9] TheCollaborative Asteroid Lightcurve Link adoptsPetr Pravec's revised WISE-data, that is, an albedo of 0.3498 and a diameter of 4.80 kilometers based on anabsolute magnitude of 13.35.[5][10]
