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2006 Polonskaya (provisional designation: 1973 SB₃) is a stony Flora asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered on 22 September 1973, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula, and later named after Ukrainian astronomer Elena Kazimirtchak-Polonskaïa. Its one-kilometer-sized satellite was discovered by an international collaboration of astronomers in November 2005.

Classification and orbit

Polonskaya is a member of the Flora family, one of the largest collisional populations of stony asteroids, when applying the synthetic hierarchical clustering method (HCM) by Nesvorný. However, according to another HCM-analysis by Milani and Knežević (AstDys), it is a background asteroid as in this analysis the Flora asteroid clan is not recognized. Polonskaya orbits the Sun in the inner 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 an eccentricity of 0.19 and an inclination of 5° with respect to the ecliptic. On 16 September 1941, it was first observed at the Finnish Turku Observatory in Finland. The body's observation arc begins in April 1950 at Palomar Mountain, about 23 years prior to its official discovery observation.

Naming

This minor planet was named after Russian astronomer Elena Ivanovna Kazimirchak-Polonskaya (1902–1992), who researched the motion and orbital evolution of comets, in particular the capture of comets by major planets. She was a member of IAU's Commission XX, and was awarded the F. A. Bredikhin prize. The official naming citation was published by the Minor Planet Center on 1 September 1978 (M.P.C. 4481).

Satellite

In 2005, it was claimed that lightcurve observations indicate that Polonskaya has a small moon about 0.99 km in diameter. 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 a trinary asteroid.

Physical characteristics

Polonskaya is considered a stony S-type asteroid with a typically high albedo due to its membership to the Flora family.

Lightcurves

Between 2005 and 2010, several rotational lightcurves of Polonskaya were obtained from photometric observations by Donald Pray, Petr Pravec, Peter Kušnirák, Walter Cooney, John Gross and Dirk Terrell. Lightcurve analysis gave a rotation period between 3.114 and 3.1183 hours with a brightness amplitude of 0.18–0.10 magnitude for the best rated results (U=3/3/3/3). A later retracted alternative period solution of 6.69±0.01 h (about twice as long) has also been proposed. In September 2019, follow-up observations by Pravec gave an unchanged rotation period of 3.1181±0.0005 h (U=3).

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Polonskaya measures 4.625 kilometers in diameter and its surface has an albedo of 0.354. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-data, that is, an albedo of 0.3498 and a diameter of 4.80 kilometers based on an absolute magnitude of 13.35.

References

1. ^ "2006 Polonskaya (1973 SB3)". Minor Planet Center. Retrieved 15 May 2021.
2. ^ Schmadel, Lutz D. (2007). "(2006) Polonskaya". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 162. doi:10.1007/978-3-540-29925-7_2007. ISBN 978-3-540-00238-3.
3. ^ "Asteroid 2006 Polonskaya – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 15 May 2021.
4. ^ "JPL Small-Body Database Browser: 2006 Polonskaya (1973 SB3)" (2017-04-30 last obs.). Jet Propulsion Laboratory. Retrieved 29 June 2017.
5. ^ "LCDB Data for (2006) Polonskaya". Asteroid Lightcurve Database (LCDB). Retrieved 15 May 2001.
6. ^ Johnston, Robert (21 September 2014). "(2006) Polonskaya". johnstonsarchive.net. Retrieved 28 May 2015.
7. ^ "IAUC 8630, 2006". Central Bureau for Astronomical Telegrams. 16 November 2005. Retrieved 23 August 2016.(ADS)
8. ^ Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
9. ^ Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68.
10. ^ Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 29 June 2017.
11. ^ Pray, D.; Pravec, P.; Kusnirak, P.; Cooney, W.; Gross, J.; Terrell, D. (November 2005). "(2006) Polonskaya". IAU Circ. 8630 (8630): 3. Bibcode:2005IAUC.8630....3P. Retrieved 29 June 2017.
12. "Asteroid 2006 Polonskaya – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 15 May 2021.
13. Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. Bibcode:2009dmpn.book.....S. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
14. Pravec, P.; Scheirich, P.; Vokrouhlický, D.; Harris, A. W.; Kusnirák, P.; Hornoch, K.; et al. (March 2012). "Binary asteroid population. 2. Anisotropic distribution of orbit poles of small, inner main-belt binaries". Icarus. 218 (1): 125–143. Bibcode:2012Icar..218..125P. doi:10.1016/j.icarus.2011.11.026.
15. Behrend, Raoul. "Asteroids and comets rotation curves – (2006) Polonskaya". Geneva Observatory. Retrieved 29 June 2017.

External links

• Asteroids with Satellites, Robert Johnston, johnstonsarchive.net
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend

• Minor planet object articles (numbered)
• Flora asteroids
• Discoveries by Nikolai Chernykh
• Named minor planets
• Binary asteroids
• Astronomical objects discovered in 1973
• Astronomical objects discovered in 2005