9991 Anežka
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 after
Anežka Moravcová
(discoverer's grandmother)[2]
1997 TY7 · 1977 DX9
1983 GV1 · 1994 BZ
main-belt · Themis [3]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc40.19 yr (14,681 days)
Aphelion3.7082 AU
Perihelion2.6975 AU
3.2028 AU
Eccentricity0.1578
5.73 yr (2,094 days)
356.19°
0° 10m 19.2s / day
Inclination2.1773°
80.608°
115.62°
Physical characteristics
Dimensions7.92 km (calculated)[3]
12.293±0.294 km[4][5]
4.4692±0.0019 h[6]
0.08 (assumed)[3]
0.097±0.013[4][5]
C [3]
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 (U=2).[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 2 3 4 "JPL Small-Body Database Browser: 9991 Anezka (1997 TY7)" (2017-05-01 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
    2. 1 2 3 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. 1 2 3 4 5 6 "LCDB Data for (9991) Anezka". Asteroid Lightcurve Database (LCDB). Retrieved 1 August 2016.
    4. 1 2 3 4 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.
    5. 1 2 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.
    6. 1 2 3 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.
    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. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 1 August 2016.
    8. 1 2 "9991 Anezka (1997 TY7)". Minor Planet Center. Retrieved 1 August 2016.
    9. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 1 August 2016.
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