is a highly eccentric, stony
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
, classified as a
near-Earth object
A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...
of the
Amor group of asteroids, approximately 3 kilometers in diameter. It was discovered on 22 June 1993, by American astronomers
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 ...
and
Kenneth Lawrence at the U.S.
Palomar Observatory
The Palomar Observatory is an astronomical research observatory in the Palomar Mountains of San Diego County, California, United States. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...
in California.
Classification and orbit
The stony
S-type asteroid
S-type (stony-type or silicaceous-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 ...
orbits the Sun at a distance of 1.1–3.7
AU once every 3 years and 10 months (1,392 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-Centre (geometry), center, in geometry
* Eccentricity (g ...
of 0.54 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 reference plane and the orbital plane or axis of direction of the orbiting object.
For a satellite orbiting the Eart ...
of 8
° with respect to the
ecliptic
The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making.
Fr ...
.
It has an Earth
minimum orbital intersection distance of nearly , which corresponds to 71.8
lunar distance
The instantaneous Earth–Moon distance, or distance to the Moon, is the distance from the center of Earth to the center of the Moon. In contrast, the Lunar distance (LD or \Delta_), or Earth–Moon characteristic distance, is a unit of measure ...
s. As it crosses the orbit of Mars, it may also be classified as a
Mars-crosser, and, on 28 November 2023, it will pass from the Red Planet.
[ The first ]precovery
In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This ha ...
was taken at the Australian Siding Spring Observatory
Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...
in 1981, 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 12 years prior to its discovery.
Physical characteristics
Since the 1990s, and up to June 2016, four well-defined rotational lightcurve
In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...
s were obtained for this asteroid from photometric observations, giving a rotation period
In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the objec ...
of approximately 4.95 hours with a high brightness variation between 0.53 and 0.82 in 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 ...
, indicating that the asteroid has a non-spheroidal shape. In the 1990s, Italian astronomer Stefano Mottola obtained a lightcurve at La Silla during the EUNEASO, a European near-Earth object search and follow-up observation program to determine additional physical parameters ().
Diameter
While in the 1990s, Stefano Mottola estimated the asteroid to measure 3.8 kilometers in diameter (H = 15.03),albedo
Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...
for stony asteroids of 0.20 and derives a shorter diameter of 2.8 kilometers, based on an absolute magnitude of 15.14.
Notes
References
External links
Asteroid Lightcurve Database (LCDB)
query form
)
Dictionary of Minor Planet Names
Google books
– Observatoire de Genève, Raoul Behrend
*
*
*
{{DEFAULTSORT:1993 MF
005836
Discoveries by Eleanor F. Helin
Discoveries by Kenneth J. Lawrence
005836
19930622