31179 Gongju (
provisional designation
Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...
) is a stony Nysian
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.
...
from the inner regions of the
asteroid belt, approximately in diameter. It was discovered on 21 December 1997, by Japanese amateur astronomer
Naoto Sato
is a masculine Japanese given name.
Possible writings
Naoto can be written using different kanji characters and can mean:
*直人, "honesty, person"
*尚人, "esteem, person"
*直登, "honesty, ascend"
*尚登, "esteem, ascend"
*直斗, "honest ...
at his
Chichibu Observatory near Tokyo, central Japan.
The
S-type asteroid has a
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 4.8 hours and possibly an elongated shape.
It was named for the South Korean city of
Gongju.
Orbit and classification
Gongju is a member of the
Nysa family
The Nysa family (adj. ''Nysian''; FIN: 405) is part of the Nysa–Polana complex, the largest cluster of asteroid families in the asteroid belt. It is located in the inner region of the asteroid belt, orbiting the Sun between 2.41 and 2.5 A ...
(),
the largest
asteroid family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An a ...
of the main belt, consisting of stony and carbonaceous subfamilies. The family, named after
44 Nysa
Nysa ( minor planet designation: 44 Nysa) is a large and very bright main-belt asteroid, and the brightest member of the Nysian asteroid family. It is classified as a rare class E asteroid and is probably the largest of this type (though 55 P ...
, is located near the 3:1
orbital resonance with Jupiter, a depleted zone that separates the inner from the intermediate asteroid belt.
It orbits the Sun in the
inner
Interior may refer to:
Arts and media
* ''Interior'' (Degas) (also known as ''The Rape''), painting by Edgar Degas
* ''Interior'' (play), 1895 play by Belgian playwright Maurice Maeterlinck
* ''The Interior'' (novel), by Lisa See
* Interior de ...
asteroid belt at a distance of 2.0–2.9
AU once every 3 years and 10 months (1,394 days;
semi-major axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...
of 2.44 AU). Its orbit has an
eccentricity of 0.19 and an
inclination of 3
° with respect to the
ecliptic.
The body's
observation arc begins with its observations as at ESO's
La Silla Observatory in October 1989, more than 8 years prior to its official discovery observation at Chichibu.
Physical characteristics
Based on the Moving Object Catalog (MOC) of the
Sloan Digital Sky Survey
The Sloan Digital Sky Survey or SDSS is a major multi-spectral imaging and spectroscopic redshift survey using a dedicated 2.5-m wide-angle optical telescope at Apache Point Observatory in New Mexico, United States. The project began in 2000 a ...
, Gongju has a
spectral type of a stony
S-type asteroid.
Rotation period
In October 2012, a rotational
lightcurve of Gongju was obtained from
photometric observations by American astronomer
John Ruthroff at the Shadowbox Observatory in Indiana. Lightcurve analysis gave a well-defined
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 4.829 hours with a high brightness amplitude of 0.80
magnitude, indicative of a non-spherical shape ().
Diameter and albedo
According to the survey carried out by the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer, Gongju measures 4.675 kilometers in diameter and its surface has an
albedo of 0.353,
while the ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.21 and calculates a diameter of 5.04 kilometers based on an
absolute magnitude of 13.8.
Naming
This
minor planet was named after the South Korean city of
Gongju, located in Chungcheongnam Province. It has a population of approximately 120,000 and was the capital of Baekje dynasty in the 5th century AD and the seat of the provincial government until 1932.
The official naming citation 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 14 May 2014 ().
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Minor Planet Center
*
*
{{DEFAULTSORT:Gongju
031179
Discoveries by Naoto Sato
Named minor planets
19971221