2062 Aten

2062 Aten /ˈɑːtən/,[lower-alpha 1] provisional designation 1976 AA, is a stony sub-kilometer asteroid and namesake of the Aten asteroids, a subgroup of near-Earth objects. The asteroid was named after Aten from Egyptian mythology.

2062 Aten
Orbit of Aten at epoch September 2013
Discovery [1][2]
Discovered byE. F. Helin
Discovery sitePalomar Obs.
Discovery date7 January 1976
Designations
(2062) Aten
Pronunciation/ˈɑːtən/
Named after
Aten (Egyptian mythology)[3]
1976 AA
Aten · NEO [1][2]
Orbital characteristics [1]
Epoch 31 December 2011 (JD 2455926.5)
Uncertainty parameter 0
Observation arc59.14 yr (21,601 days)
Earliest precovery date17 December 1955
Aphelion1.1434 AU
Perihelion0.7901 AU
0.9668 AU
Eccentricity0.1827
0.95 yr (347 days)
172.27°
1° 2m 12.48s / day
Inclination18.934°
108.60°
148.04°
Earth MOID0.1131 AU · 44.1 LD
Physical characteristics
Dimensions0.73±0.03 km[4]
0.80±0.03 km[5]
0.91 km[6]
1.1 km[7]
1.30 km[8]
40.77 h[9]
0.20[8]
0.20±0.15[10]
0.26[7]
0.28[6]
0.39±0.05[4]
0.52±0.10[5]
S (Tholen)[1] · Sr (SMASS)[1]
B–V = 0.930[1]
U–B = 0.460[1]
16.80[1][5] · 17.01±1.40[11] · 17.12[9] · 17.20[12][6] · 17.30[4]

    It was discovered on 7 January 1976, at the Palomar Observatory by American astronomer Eleanor Helin,[2] who was the principal scientist for the NEAT project until her retirement in 2002. The S-type asteroid measures approximately 900 meters in diameter, has a longer-than average rotation period of 44.77 hours, and approaches the orbit Earth to 44.1 lunar distances.

    Orbit and classification

    Aten orbits the Sun at a distance of 0.8–1.1 AU once every 11 months (347 days). Its orbit has an eccentricity of 0.18 and an inclination of 19° with respect to the ecliptic.[1] A first precovery was taken at the discovering observatory in December 1955, extending the body's observation arc by more than 20 years prior to its official discovery observation.[2]

    Namesake of the Aten group

    Aten was the first asteroid found to have a semi-major orbital axis of less than one astronomical unit and a period of less than one year.[3] A new category of asteroids was thus created, the Atens. As of 2017, the group consists of more than 1,200 numbered members. Other groups of near-Earth objects (NEOs) are the Apollo and Amor asteroids, which are both significantly larger than the Atens, while the Atira asteroids form the smallest NEO-group by far.[13]

    Close approaches

    The asteroid has an Earth minimum orbit intersection distance of 0.1131 AU (16,900,000 km) which corresponds to 44.1 lunar distances.[1]

    Physical characteristics

    In the Tholen classification, Aten is a common S-type asteroid. In the SMASS taxonomy it is classified as an Sr-type, a subtype which transitions to the R-type asteroids.[1]

    Lightcurve

    In the 1990s, Italian astronomer Stefano Mottola obtained a rotational lightcurve of Aten during the EUNEASO survey at La Silla, which was a European near-Earth object search and follow-up observation program to determine additional physical parameters. Lightcurve analysis gave a longer-than average rotation period of 40.77 hours with a brightness variation of 0.26 magnitude (U=2).[9] No additional lightcurves have been obtained since.[12]

    Diameter and albedo

    According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Aten measures between 700 and 830 meters in diameter and its surface has a high albedo between 0.39 and 0.52.[4][5]

    in 1994, Tom Gehrels published a diameter of 1.1 kilometers and an albedo of 0.26 in his book Hazards Due to Comets and Asteroids.[1][7] The Warm Spitzer NEO survey ("ExploreNEOs") gives a diameter of 1.3 kilometers with an albedo of 0.20.[8]

    The Collaborative Asteroid Lightcurve Link agrees with a revised thermal model for asteroid diameters and albedos, and adopts an albedo of 0.28 with a diameter of 0.91 kilometers based on an absolute magnitude of 17.2.[6][12] However, the Minor Planet Center (MPC) classifies Aten as a larger "1+ KM" object.[2]

    Naming

    This minor planet was named from Egyptian mythology after Aten, the ancient Egyptian god of the solar disk, originally an aspect of the god Ra.[3] The official naming citation was published by the Minor Planet Center on 1 August 1978 (M.P.C. 4420).[14]

    Notes
    1. Oxford English Dictionary

    References
    1. "JPL Small-Body Database Browser: 2062 Aten (1976 AA)" (2015-02-06 last obs.). Jet Propulsion Laboratory. Retrieved 3 August 2017.
    2. "2062 Aten (1976 AA)". Minor Planet Center. Retrieved 3 August 2017.
    3. Schmadel, Lutz D. (2007). "(2062) Aten". Dictionary of Minor Planet Names – (2062) Aten. Springer Berlin Heidelberg. p. 167. doi:10.1007/978-3-540-29925-7_2063. ISBN 978-3-540-00238-3.
    4. 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. Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117.
    6. Harris, Alan W. (February 1998). "A Thermal Model for Near-Earth Asteroids". Icarus. 131 (2): 291–301. Bibcode:1998Icar..131..291H. doi:10.1006/icar.1997.5865.
    7. Tom Gehrels; Mildred Shapley Matthews; A. M. Schumann (1994). Hazards Due to Comets and Asteroids. University of Arizona Press. pp. 540–543. ISBN 978-0-8165-1505-9.
    8. Harris, A. W.; Mommert, M.; Hora, J. L.; Mueller, M.; Trilling, D. E.; Bhattacharya, B.; et al. (March 2011). "ExploreNEOs. II. The Accuracy of the Warm Spitzer Near-Earth Object Survey" (PDF). The Astronomical Journal. 141 (3): 10. Bibcode:2011AJ....141...75H. doi:10.1088/0004-6256/141/3/75.
    9. Mottola, S.; de Angelis, G.; di Martino, M.; Erikson, A.; Harris, A. W.; Hahn, G.; et al. (March 1995). "The EUNEASO Photometric Follow-up Program". Abstracts of the Lunar and Planetary Science Conference. 26: 1003. Bibcode:1995LPI....26.1003M.
    10. Thomas, C. A.; Trilling, D. E.; Emery, J. P.; Mueller, M.; Hora, J. L.; Benner, L. A. M.; et al. (September 2011). "ExploreNEOs. V. Average Albedo by Taxonomic Complex in the Near-Earth Asteroid Population". The Astronomical Journal. 142 (3): 12. Bibcode:2011AJ....142...85T. doi:10.1088/0004-6256/142/3/85.
    11. 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.
    12. "LCDB Data for (2062) Aten". Asteroid Lightcurve Database (LCDB). Retrieved 3 August 2017.
    13. "Discovery Statistics". CNEOS / JPL. Retrieved 3 August 2017.
    14. 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. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
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