Colonel William A. Phillips

1648 Shajna, provisional designation 1935 RF, is a stony asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 5 September 1935, by Russian astronomer Pelageya Shajn at Simeiz Observatory on the Crimean peninsula.[12] Two weeks later, it was independently discovered by Cyril Jackson at Johannesburg Observatory, South Africa. It was later named after the discoverer and her husband, Russian astronomers Grigory Shajn.[2]

Orbit and classification

Shajna orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,221 days). Its well-determined orbit has an eccentricity of 0.21 and an inclination of 5° with respect to the ecliptic.[1] In 1921, Shajna was first identified as 1921 GB at Heidelberg Observatory. Its first used observation was taken at Uccle in 1934, when it was identified as 1934 CK1, extending the body's observation arc by one year prior to its official discovery observation.[12]

Rotation period

In July 2005, a rotational lightcurve of was obtained by French amateur astronomer Laurent Bernasconi. It gave a well-defined rotation period of 6.4140 hours with a brightness variation of 0.65 magnitude (U=3).[10] Two modeled lightcurves from various surveys including the Lowell photometric database gave similar periods of 6.41368 and 6.41369 hours (U=n.a.).[8][9] Photometric observations at the Palomar Transient Factory in September 2012, gave nearly identical periods of 6.4140 and 6.4248 hours in the R- and S-band, respectively (U=2/2).[11]

Diameter and albedo

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Shajna measures between 8.26 and 9.45 kilometers in diameter, and its surface has an albedo between 0.191 and 0.35.[4][5][6][7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 9.23 kilometers with an absolute magnitude of 12.54.[3]

Naming

This minor planet was named in honor of the late couple of Russian astronomers Grigory Shajn (1892–1956) and the discoverer herself, Pelageya Shajn (1894–1956), first woman ever to discover a minor planet. The asteroid 1190 Pelagia is also named after her, while her husband is honored by the lunar crater Shayn.[2] The official naming citation was published by the Minor Planet Center on 20 February 1962 (M.P.C. 2117).[13]

References

  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1648 Shajna (1935 RF)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 30 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1648) Shajna". Dictionary of Minor Planet Names – (1648) Shajna. Springer Berlin Heidelberg. p. 131. doi:10.1007/978-3-540-29925-7_1649. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1648) Shajna". Asteroid Lightcurve Database (LCDB). Retrieved 26 December 2016.
  4. ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63.
  5. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. S2CID 46350317. Retrieved 26 December 2016.
  6. ^ a b c d 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. S2CID 35447010.
  7. ^ a b c 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. S2CID 118745497. Retrieved 26 December 2016.
  8. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. S2CID 118427201. Retrieved 26 December 2016.
  9. ^ a b Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441. S2CID 119112278.
  10. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1648) Shajna". Geneva Observatory. Retrieved 26 December 2016.
  11. ^ a b c d Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. S2CID 8342929. Retrieved 26 December 2016.
  12. ^ a b "1648 Shajna (1935 RF)". Minor Planet Center. Retrieved 26 December 2016.
  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.

External links

source: https://en.wikipedia.org/wiki/1648_Shajna