Astronomy:9991 Anežka

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9991 Anežka
AnimatedOrbitOf9991Anezka.gif
Orbit comparison of 9991 Anežka (blue), inner planets (red) and Jupiter (outermost)
Discovery [1]
Discovered byZ. Moravec
Discovery siteKleť Obs.
Discovery date5 October 1997
Designations
(9991) Anezka
Named afterAnežka Moravcová
(discoverer's grandmother)[2]
1997 TY7 · 1977 DX9
1983 GV1 · 1994 BZ
Minor planet categorymain-belt · Themis[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc40.19 yr (14,681 days)
|{{{apsis}}}|helion}}3.7082 AU
|{{{apsis}}}|helion}}2.6975 AU
3.2028 AU
Eccentricity0.1578
Orbital period5.73 yr (2,094 days)
Mean anomaly356.19°
Mean motion0° 10m 19.2s / day
Inclination2.1773°
Longitude of ascending node80.608°
115.62°
Physical characteristics
Dimensions7.92 km (calculated)[3]
12.293±0.294 km[4][5]
Rotation period4.4692±0.0019 h[6]
Geometric albedo0.08 (assumed)[3]
0.097±0.013[4][5]
C[3]
Absolute magnitude (H)12.7[4] · 13.3[1] · 13.415±0.003 (R)[6] · 13.86[3] · 13.89±0.32[7]


9991 Anežka, provisional designation 1997 TY7, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 10 kilometers in diameter.

The asteroid was discovered on 5 October 1997, by Czech astronomer Zdeněk Moravec at the South Bohemian Kleť Observatory in the Czech Republic.[8] It was named after the discoverer's grandmother, Anežka Moravcová.[2]

Orbit and classification

Anežka is a carbonaceous asteroid and member of the Themis family, a dynamical family of outer main-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.7–3.7 AU once every 5 years and 9 months (2,094 days). Its orbit has an eccentricity of 0.16 and an inclination of 2° with respect to the ecliptic.[1] It was first identified as 1977 DX9 at the Japanese Kiso Observatory in 1977, extending the body's observation arc by 20 years prior to its discovery.[8]

Physical characteristics

Rotation period

A rotational lightcurve for this asteroid was obtained from photometric observations at the Palomar Transient Factory in December 2012. It gave it a rotation period of 4.4692±0.0019 hours with a brightness variation of 0.24 in magnitude ({{{1}}}).[6]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 12.3 kilometers in diameter and its surface has an albedo of 0.097,[4] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 7.9 kilometers.[3]

Naming

This minor planet was named after the discoverer's grandmother, Anežka Moravcová (b 1924), on her 75th birthday.[2] The official naming citation was published by the Minor Planet Center on 4 May 1999 (M.P.C. 34632).[9]

References

  1. 1.0 1.1 1.2 1.3 "JPL Small-Body Database Browser: 9991 Anezka (1997 TY7)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009991. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(9991) Anežka". Dictionary of Minor Planet Names – (9991) Anežka. Springer Berlin Heidelberg. p. 716. doi:10.1007/978-3-540-29925-7_7780. ISBN 978-3-540-00238-3. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 "LCDB Data for (9991) Anezka". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9991%7CAnezka. 
  4. 4.0 4.1 4.2 4.3 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. doi:10.1088/0004-637X/741/2/90. Bibcode2011ApJ...741...90M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...90M. Retrieved 1 August 2016. 
  5. 5.0 5.1 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. doi:10.1088/0004-637X/741/2/68. Bibcode2011ApJ...741...68M. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M. Retrieved 4 December 2016. 
  6. 6.0 6.1 6.2 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. doi:10.1088/0004-6256/150/3/75. Bibcode2015AJ....150...75W. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W. Retrieved 1 January 2016. 
  7. 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. doi:10.1016/j.icarus.2015.08.007. Bibcode2015Icar..261...34V. http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V. Retrieved 1 August 2016. 
  8. 8.0 8.1 "9991 Anezka (1997 TY7)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=9991. 
  9. "MPC/MPO/MPS Archive". Minor Planet Center. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html. 

External links