6522 Aci

6522 Aci
Discovery [1]
Discovered by E. F. Helin
Discovery site Palomar Obs.
Discovery date 9 July 1991
Designations
MPC designation 6522 Aci
Named after
 Aci (Greek mythology
and river in Sicily)[2]
1991 NQ · 1990 BH4
main-belt · Phocaea [3]
Orbital characteristics [1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 26.23 yr (9,582 days)
Aphelion 2.8601 AU
Perihelion 1.9106 AU
2.3853 AU
Eccentricity 0.1990
3.68 yr (1,346 days)
321.75°
0° 16m 3s / day
Inclination 22.109°
294.45°
314.12°
Physical characteristics
Dimensions 6.125±0.119 km[4]
5.65 km (calculated)[3]
7.6921±0.0017 h[5]
0.3916±0.0286[4]
0.23 (assumed)[3]
S [3]
12.7[4]
13.0[1]
13.003±0.005 (R)[5]
13.16±0.30[6]
13.45[3]

    6522 Aci, provisional designation 1991 NQ, is a stony Phocaea asteroid from the inner regions of the asteroid belt, about 6 kilometers in diameter. It was discovered by American female astronomer Eleanor Helin at the U.S. Palomar Observatory in California, on 9 July 1991.[7]

    The S-type asteroid is a member of the Phocaea family, a relatively small group of asteroids with similar orbital characteristics. It orbits the Sun at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,346 days). Its orbit has an eccentricity of 0.20 and an inclination of 22° with respect to the ecliptic.[1] The first precovery was taken at the German Karl Schwarzschild Observatory in 1990, one year prior to its discovery.[7]

    A photometric light-curve analysis performed at the U.S. Palomar Transient Factory in 2010, rendered a rotation period of 7.6921±0.0017 hours with a brightness amplitude of 0.68 in magnitude (U=2).[5] According to the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 6.1 kilometers in diameter and its surface has a high albedo of 0.39, [4] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.23 – which derives from 25 Phocaea, namesake and largest member of this orbital family – and calculates a diameter of 5.7 kilometers.[3]

    The minor planet was named for the river southeast of Mount Etna in Sicily, Italy. The towns and villages along the river, such as Aci Castello, Aci Trezza, Aci-Reale, and Aci Sant'Antonio, were also honored. The river also brings to mind the myth of Aci from Greek mythology, which is about a young Sicilian shepherd, who was killed by the jealous cyclops Polyphemus, because of his love for the sea nymph Galatea. The minor planet 74 Galatea is named after this Nereid.[2] Naming citation was published on 26 October 1996 (M.P.C. 28090).[8]

    References

    1. 1 2 3 4 "JPL Small-Body Database Browser: 6522 Aci (1991 NQ)" (2016-04-19 last obs.). Jet Propulsion Laboratory. Retrieved 28 April 2016.
    2. 1 2 Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (6522) Aci. Springer Berlin Heidelberg. p. 539. ISBN 978-3-540-00238-3. Retrieved 28 April 2016.
    3. 1 2 3 4 5 6 "LCDB Data for (6522) Aci". Asteroid Lightcurve Database (LCDB). Retrieved 28 April 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 28 April 2016.
    5. 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:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 28 April 2016.
    6. ↑ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 28 April 2016.
    7. 1 2 "6522 Aci (1991 NQ)". Minor Planet Center. Retrieved 28 April 2016.
    8. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 28 April 2016.

    External links

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