2830 Greenwich ( ''prov. designation'': ) is a bright

Phocaea asteroid The Phocaea family ( ; adj. ''Phocaean''; ) is a collisional family of asteroids located between 2.25 and 2.5 AU in the inner region of the asteroid belt. Phocaea asteroids are of stony S-type composition and have orbits with eccentricities ...

from the inner regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

. It was discovered on 14 April 1980, by American astronomer

Edward Bowell Edward L. G. "Ted" Bowell (born 1943 in London), is an American astronomer. Bowell was educated at Emanuel School London, University College, London, and the University of Paris. He was principal investigator of the Lowell Observatory Near-Earth ...

at Lowell's U.S.

Anderson Mesa Station Anderson Mesa Station is an astronomical observatory established in 1959 as a dark-sky observing site for Lowell Observatory. It is located at Anderson Mesa in Coconino County, Arizona, about 12 miles southeast of Lowell's main campus on Mars H ...

, Arizona, and named for the historical

Royal Greenwich Observatory The Royal Observatory, Greenwich (ROG; known as the Old Royal Observatory from 1957 to 1998, when the working Royal Greenwich Observatory, RGO, temporarily moved south from Greenwich to Herstmonceux) is an observatory situated on a hill in G ...

in England. The stony

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 ...

has a long

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 24 hours and measures approximately in diameter

Classification and orbit

''Greenwich'' is a member of the Phocaea family (), a group of asteroids with similar orbital characteristics. 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 ...

main-belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,340 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 0.21 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 25 ° 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 ...

. It was first identified as at

Crimea-Nauchnij The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name ...

in 1969, extending the asteroid'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 11 years prior to its official discovery observation at Anderson Mesa.

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 ...

is named for the

, home of the

Astronomer Royal Astronomer Royal is a senior post in the Royal Households of the United Kingdom. There are two officers, the senior being the Astronomer Royal dating from 22 June 1675; the junior is the Astronomer Royal for Scotland dating from 1834. The post ...

and located in the London borough of Greenwich, England. The naming took place on the occasion of the centennial of its adoption as "the Greenwich prime meridian for longitude and time". Founded for naval purposes in 1675, the Royal Observatory quickly became a leading institution in astronomy. In 1884, the prime meridian finally became a worldwide standard. 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 15 May 1984 ().

Physical characteristics

In the Tholen taxonomy, ''Greenwich'' is classified as a stony

Lightcurves

In May 2002, a photometric

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 ...

analysis by French amateur astronomer Christophe Demeautis gave an ambiguous

of 24 hours with a brightness variation of 0.5 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 ...

().

Diameter and albedo

According to the surveys 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, ''Greenwich'' measures between 7.9 and 9.5 kilometers in diameter, and its surface has an

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 0.17 and 0.19. The ''Collaborative Asteroid Lightcurve Link'' adopts

Petr Pravec Petr Pravec (born September 17, 1967) is a Czech astronomer and a discoverer of minor planets, born in Třinec, Czech Republic. Pravec is a prolific discoverer of binary asteroids, expert in photometric observations and rotational lightcurves a ...

's revised WISE-results, that is, a diameter of 9.252 kilometer with an albedo of 0.1865 and 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 12.61.

References

External links

Lightcurve Database Query
(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names
Google books

– ''Geneva Observatory'',

Raoul Behrend 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 num ...

Discovery Circumstances: Numbered Minor Planets (1)-(5000)
– Minor Planet Center * * {{DEFAULTSORT:Greenwich 002830 Discoveries by Edward L. G. Bowell Named minor planets 002830 19800414