2062 Aten , provisional designation , is a stony sub-kilometer
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
and namesake of the
Aten asteroid
The Aten asteroids are a dynamical group of asteroids whose orbits bring them into proximity with Earth. By definition, Atens are Earth-crossing asteroids . The group is named after 2062 Aten, the first of its kind, discovered on 7 Januar ...
s, a subgroup of
near-Earth object
A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...
s. The asteroid was named after
Aten
Aten also Aton, Atonu, or Itn ( egy, jtn, ''reconstructed'' ) was the focus of Atenism, the religious system established in ancient Egypt by the Eighteenth Dynasty pharaoh Akhenaten. The Aten was the disc of the sun and originally an aspect of ...
from
Egyptian mythology
Egyptian mythology is the collection of myths from ancient Egypt, which describe the actions of the Egyptian gods as a means of understanding the world around them. The beliefs that these myths express are an important part of ancient Egyptia ...
.
It was discovered on 7 January 1976, at the
Palomar Observatory
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...
by American astronomer
Eleanor Helin
Eleanor Francis "Glo" Helin (née Francis, 19 November 1932 – 25 January 2009) was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory. (Some sources gi ...
,
who was the principal scientist for the
NEAT
Neat may refer to:
* Neat (bartending), a single, unmixed liquor served in a rocks glass
* Neat, an old term for horned oxen
* Neat Records, a British record label
* Neuroevolution of augmenting topologies (NEAT), a genetic algorithm (GA) for the ...
project until her retirement in 2002. The
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
measures approximately 900 meters in diameter, has a longer-than average
rotation period
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...
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
Eccentricity or eccentric may refer to:
* Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal"
Mathematics, science and technology Mathematics
* Off-center, in geometry
* Eccentricity (graph theory) of a v ...
of 0.18 and an
inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...
of 19
° with respect to the
ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...
.
A first
precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of an object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This happens mos ...
was taken at the discovering observatory in December 1955, extending the body's
observation arc
In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...
by more than 20 years prior to its official discovery observation.
Namesake of the Aten group
''Aten'' was the first asteroid found to have a
semi-major orbital axis of less than one
astronomical unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...
and a period of less than one year.
A new category of asteroids was thus created, the
Atens
The Aten asteroids are a dynamical group of asteroids whose orbits bring them into proximity with Earth. By definition, Atens are Earth-crossing asteroids . The group is named after 2062 Aten, the first of its kind, discovered on 7 Januar ...
. As of 2017, the group consists of more than 1,200 numbered members. Other groups of near-Earth objects (NEOs) are the
Apollo
Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...
and
Amor asteroids, which are both significantly larger than the Atens, while the
Atira asteroid
Atira asteroids or Apohele asteroids, also known as interior-Earth objects (IEOs), are asteroids whose orbits are entirely confined within Earth's orbit; that is, their orbit has an aphelion (farthest point from the Sun) smaller than Earth's peri ...
s form the smallest NEO-group by far.
Close approaches
The asteroid has an Earth
minimum orbit intersection distance
Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of ...
of which corresponds to 44.1
lunar distances.
Physical characteristics
In the
Tholen classification
An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ...
, ''Aten'' is a common
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
. In the
SMASS taxonomy it is classified as an Sr-type, a subtype which transitions to the
R-type asteroid R-type asteroids are moderately bright, relatively uncommon inner-belt asteroids that are spectrally intermediate between the V and A-type asteroids. The spectrum shows distinct olivine and pyroxene features at 1 and 2 micrometres, with a possibil ...
s.
Lightcurve
In the 1990s, Italian astronomer
Stefano Mottola
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 numb ...
obtained a rotational
lightcurve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...
of ''Aten'' during the EUNEASO survey at
La Silla La Silla may refer to:
* La Silla Observatory, an astronomical observatory in Chile
* Cerro de la Silla, a mountain and natural monument located within the metropolitan area of the city of Monterrey, Nuevo León, in northeastern Mexico.
* La Sill ...
, 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
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...
of 40.77 hours with a brightness variation of 0.26
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
().
No additional lightcurves have been obtained since.
Diameter and albedo
According to the survey carried out by NASA's
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
with its subsequent
NEOWISE
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
mission, ''Aten'' measures between 700 and 830 meters in diameter and its surface has a high
albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
between 0.39 and 0.52.
in 1994,
Tom Gehrels
Anton M.J. "Tom" Gehrels (February 21, 1925 – July 11, 2011) was a Dutch–American astronomer, Professor of Planetary Sciences, and Astronomer at the University of Arizona, Tucson.
Biography
Youth and education
Gehrels was born at Haa ...
published a diameter of 1.1 kilometers and an albedo of 0.26 in his book ''Hazards Due to Comets and Asteroids''.
The Warm Spitzer NEO survey ("ExploreNEOs") gives a diameter of 1.3 kilometers with an albedo of 0.20.
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
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...
of 17.2.
However, the
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
(MPC) classifies ''Aten'' as a larger "1+ KM" object.
Naming
This
minor planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...
was named from
Egyptian mythology
Egyptian mythology is the collection of myths from ancient Egypt, which describe the actions of the Egyptian gods as a means of understanding the world around them. The beliefs that these myths express are an important part of ancient Egyptia ...
after
Aten
Aten also Aton, Atonu, or Itn ( egy, jtn, ''reconstructed'' ) was the focus of Atenism, the religious system established in ancient Egypt by the Eighteenth Dynasty pharaoh Akhenaten. The Aten was the disc of the sun and originally an aspect of ...
, the ancient
Egyptian god
Ancient Egyptian deities are the gods and goddesses worshipped in ancient Egypt. The beliefs and rituals surrounding these gods formed the core of ancient Egyptian religion, which emerged sometime in prehistory. Deities represented natural fo ...
of the solar disk, originally an aspect of the god
Ra.
The official was published by the
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
on 1 August 1978 ().
Notes
References
External links
Benner, et al. - Radar Detection of Near-Earth Asteroids 2062 Aten, 2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN (1997)Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Observatoire de Genève, Raoul Behrend
*
*
*
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Discoveries by Eleanor F. Helin
Named minor planets
Earth-crosser asteroids
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