 Orbit comparison of 9991 Anežka (blue), inner planets (red) and Jupiter (outermost) | |
| Discovery | |
|---|---|
| Discovered by | Z. Moravec |
| Discovery site | Kleť Obs. |
| Discovery date | 5 October 1997 |
| Designations | |
| MPC designation | (9991) Anezka |
| Named after | Anežka Moravcová (discoverer's grandmother) |
| Alternative designations | 1997 TY7 · 1977 DX9 1983 GV1 · 1994 BZ |
| Minor planet category | main-belt · Themis |
| Orbital characteristics | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 40.19 yr (14,681 days) |
| Aphelion | 3.7082 AU |
| Perihelion | 2.6975 AU |
| Semi-major axis | 3.2028 AU |
| Eccentricity | 0.1578 |
| Orbital period (sidereal) | 5.73 yr (2,094 days) |
| Mean anomaly | 356.19° |
| Mean motion | 0° 10 19.2 / day |
| Inclination | 2.1773° |
| Longitude of ascending node | 80.608° |
| Argument of perihelion | 115.62° |
| Physical characteristics | |
| Dimensions | 7.92 km (calculated) 12.293±0.294 km |
| Synodic rotation period | 4.4692±0.0019 h |
| Geometric albedo | 0.08 (assumed) 0.097±0.013 |
| Spectral type | C |
| Absolute magnitude (H) | 12.7 · 13.3 · 13.415±0.003 (R) · 13.86 · 13.89±0.32 |
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. It was named after the discoverer's grandmother, Anežka Moravcová.
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. 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.
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 (U=2).
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, while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a diameter of 7.9 kilometers.
Naming
This minor planet was named after the discoverer's grandmother, Anežka Moravcová (b 1924), on her 75th birthday. The official naming citation was published by the Minor Planet Center on 4 May 1999 (M.P.C. 34632).
References
- ^ "JPL Small-Body Database Browser: 9991 Anezka (1997 TY7)" (2017-05-01 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
- ^ 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.
- ^ "LCDB Data for (9991) Anezka". Asteroid Lightcurve Database (LCDB). Retrieved 1 August 2016.
- ^ 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. Retrieved 1 August 2016.
- ^ 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 4 December 2016.
- ^ 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. Retrieved 1 January 2016.
- 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 1 August 2016.
- ^ "9991 Anezka (1997 TY7)". Minor Planet Center. Retrieved 1 August 2016.
- "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 1 August 2016.
External links
- 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 (5001)-(10000) – Minor Planet Center
- 9991 Anežka at AstDyS-2, Asteroids—Dynamic Site
- 9991 Anežka at the JPL Small-Body Database
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