Discovery [1] [2] | |
---|---|
Discovered by | E. F. Helin |
Discovery site | Palomar Obs. |
Discovery date | 7 January 1976 |
Designations | |
(2062) Aten | |
Pronunciation | /ˈɑːtən/ |
Named after | Aten ( Egyptian mythology) [3] |
1976 AA | |
Aten · NEO [1] [2] | |
Symbol | |
Orbital characteristics [1] | |
Epoch 31 December 2011 ( JD 2455926.5) | |
Uncertainty parameter 0 | |
Observation arc | 59.14 yr (21,601 days) |
Earliest precovery date | 17 December 1955 |
Aphelion | 1.1434 AU |
Perihelion | 0.7901 AU |
0.9668 AU | |
Eccentricity | 0.1827 |
0.95 yr (347 days) | |
172.27 ° | |
1° 2m 12.48s / day | |
Inclination | 18.934° |
108.60° | |
148.04° | |
Earth MOID | 0.1131 AU · 44.1 LD |
Physical characteristics | |
Dimensions | 0.73±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] | |
2062 Aten /ˈɑːtən/, [a] 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.
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.
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]
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]
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]
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]
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]
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]
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]