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4868 Knushevia, provisional designation 1989 UN₂, is a bright Hungaria asteroid and suspected binary system from the innermost regions of the asteroid belt, approximately 2 kilometers in diameter. It was discovered on 27 October 1989, by American astronomer Eleanor Helin at the Palomar Observatory in California, United States. The asteroid was named for the Kyiv University in Ukraine.

Classification and orbit

Knushevia is a bright member of the Hungaria family, which forms the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner main-belt at a distance of 1.8–2.1 AU once every 2 years and 9 months (1,003 days). Its orbit has an eccentricity of 0.07 and an inclination of 22° with respect to the ecliptic.

Physical characteristics

Lightcurves and satellite

Between 2008 and 2011, three rotational lightcurves of Knushevia were obtained from photometric observations by American astronomer Brian Warner. Lightcurve analysis gave a rotation period between 4.45 and 4.717 hours with an exceptionally low brightness amplitude of 0.01 magnitude (U=2/2/2).

In May 2015, Warner measured a period of 3.1422 hours with an amplitude of 0.09 (U=3). The photometric observation also revealed that Knushevia might be a binary asteroid with a minor-planet moon orbiting it every 11.922 hours. The results, however, are tentative only.

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Knushevia measures 1.535 kilometers in diameter and its surface has an outstandingly high albedo of 1.000.

The Collaborative Asteroid Lightcurve Link assumes an albedo for bright E-type asteroids of 0.40 – derived from 434 Hungaria, the family's largest member and namesake – and calculates a diameter of 2.30 kilometers based on an absolute magnitude of 14.8.

Naming

This minor planet (Ukrainian: КНУШЕВІЯ; translit.: Knushevia) was named after Kyiv University (full name Ukrainian: Київський Національний Університет ім. Т.Шевченка, translit.: Кyivs'kyj Natsional'nyj Universytet іmeni (name) Shevchenka) for its great achievement in the education, science and culture of Ukraine. It is one of the oldest and most prestigious universities in Ukraine. The approved naming citation was published by the Minor Planet Center on 27 April 2002 (M.P.C. 45336).

References

1. ^ "JPL Small-Body Database Browser: 4868 Knushevia (1989 UN2)" (2016-11-30 last obs.). Jet Propulsion Laboratory. Archived from the original on 16 September 2020. Retrieved 7 July 2017.
2. ^ Schmadel, Lutz D. (2007). "(4868) Knushevia". Dictionary of Minor Planet Names – (4868) Knushevia. Springer Berlin Heidelberg. p. 420. doi:10.1007/978-3-540-29925-7_4762. ISBN 978-3-540-00238-3.
3. ^ "4868 Knushevia (1989 UN2)". Minor Planet Center. Retrieved 7 July 2017.
4. ^ "LCDB Data for (4868) Knushevia". Asteroid Lightcurve Database (LCDB). Retrieved 7 July 2017.
5. ^ Warner, Brian D.; Stephens, Robert D. (July 2015). "The Hungaria Asteroid 4868 Knushevia: A Possible Binary". The Minor Planet Bulletin. 42 (3): 188–189. Bibcode:2015MPBu...42..188W. ISSN 1052-8091. PMID 32455357. Retrieved 7 July 2017.
6. ^ 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.
7. ^ 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. Retrieved 7 July 2017.
8. ^ Warner, Brian D. (January 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 May - September". The Minor Planet Bulletin. 36 (1): 7–13. Bibcode:2009MPBu...36....7W. ISSN 1052-8091. Retrieved 7 July 2017.
9. ^ Warner, Brian D. (July 2010). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 December - 2010 March". The Minor Planet Bulletin. 37 (3): 112–118. Bibcode:2010MPBu...37..112W. ISSN 1052-8091. Retrieved 7 July 2017.
10. ^ Warner, Brian D.; Higgins, David; Pravec, Petr; Harris, Alan W. (April 2012). "The Enigmatic Hungaria Asteroid 4868 Knushevia". The Minor Planet Bulletin. 39 (2): 82–83. Bibcode:2012MPBu...39...82W. ISSN 1052-8091. Retrieved 7 July 2017.
11. Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 7 July 2017.
12. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 7 July 2017.

External links

• Lightcurve plot of 4868 Knushevia, Palmer Divide Observatory, B. D. Warner (2011)
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 4868 Knushevia at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 4868 Knushevia at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Hungaria asteroids
• Discoveries by Eleanor F. Helin
• Named minor planets
• Binary asteroids
• Astronomical objects discovered in 1989