45 Eugenia
Encyclopedia
45 Eugenia is a large main-belt
asteroid
. It is famed as one of the first asteroids to be found to have a moon
orbiting it. It is also the second known triple asteroid, after 87 Sylvia
.
. His instrument of discovery was a 4-inch aperture telescope located in his sixth floor apartment in the Latin Quarter
of Paris
. It was the forty-fifth minor planet
to be discovered. The preliminary orbital elements were computed by Wilhelm Forster in Berlin, based on three observations in July, 1857.
The asteroid was named by its discoverer after Empress Eugenia di Montijo, the wife of Napoleon III. It was the first asteroid to be definitely named after a real person, rather than a figure from classical legend, although there was some controversy about whether 12 Victoria
was really named for the mythological figure or for Queen Victoria.
of 214 km. It is an F-type asteroid
, which means that it is very dark in colouring (darker than soot
) with a carbonaceous
composition. Like Mathilde
, its density appears to be unusually low, indicating that it may be a loosely-packed rubble pile, not a monolithic object. Eugenia appears to be almost anhydrous
.
Lightcurve analysis indicates that Eugenia's pole most likely points towards ecliptic coordinates
(β, λ) = (-30°, 124°) with a 10° uncertainty, which gives it an axial tilt
of 117°. Eugenia's rotation is then retrograde.
In November 1998, astronomers at the Canada-France-Hawaii Telescope
on Mauna Kea
, Hawaii
, discovered a small moon
orbiting Eugenia. This was the first time an asteroid moon
had been discovered by a ground-based telescope. The moon is much smaller than Eugenia, about 13 km in diameter
, and takes five days to complete an orbit around it.
The discoverers chose the name "Petit-Prince" (formally "(45) Eugenia I Petit-Prince"). This name refers to Empress Eugenia's son, the Prince Imperial
. However, the discovers also intended an allusion to the children's novella
The Little Prince
by Antoine de Saint-Exupéry
, which is about a young prince who lives on an asteroid.
"Yepun" at the European Southern Observatory
(ESO) Cerro Paranal
, in Chile
. The discovery was announced in IAUC 8817, on 7 March 2007 by Franck Marchis
and his IMCCE collaborators.
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
. It is famed as one of the first asteroids to be found to have a moon
Asteroid moon
A minor planet moon is an astronomical body that orbits a minor planet as its natural satellite. It is thought that many asteroids and Kuiper belt objects may possess moons, in some cases quite substantial in size...
orbiting it. It is also the second known triple asteroid, after 87 Sylvia
87 Sylvia
87 Sylvia is one of the largest main-belt asteroids. It is a member of the Cybele group located beyond the core of the belt . Sylvia is remarkable for being the first asteroid known to possess more than one moon....
.
Discovery
Eugenia was discovered on June 28, 1857 by the Franco-German amateur astronomer Hermann GoldschmidtHermann Mayer Salomon Goldschmidt
Hermann Mayer Salomon Goldschmidt was a German-French astronomer and painter who spent much of his life in France. He started out as a painter, but after attending a lecture by the famous French astronomer Urbain Le Verrier turned to astronomy...
. His instrument of discovery was a 4-inch aperture telescope located in his sixth floor apartment in the Latin Quarter
Latin Quarter
Latin Quarter is a part of the 5th arrondissement in Paris.Latin Quarter may also refer to:* Latin Quarter , a British pop/rock band* Latin Quarter , a 1945 British film*Latin Quarter, Aarhus, part of Midtbyen, Aarhus C, Denmark...
of Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
. It was the forty-fifth minor planet
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...
to be discovered. The preliminary orbital elements were computed by Wilhelm Forster in Berlin, based on three observations in July, 1857.
The asteroid was named by its discoverer after Empress Eugenia di Montijo, the wife of Napoleon III. It was the first asteroid to be definitely named after a real person, rather than a figure from classical legend, although there was some controversy about whether 12 Victoria
12 Victoria
12 Victoria is a large main-belt asteroid.It was discovered by J. R. Hind on September 13, 1850.Victoria is officially named after the Roman goddess of victory, but the name also honours Queen Victoria. The goddess Victoria was the daughter of Styx by the Titan Pallas...
was really named for the mythological figure or for Queen Victoria.
Physical characteristics
Eugenia is a large asteroid, with a diameterDiameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
of 214 km. It is an F-type asteroid
F-type asteroid
F-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group.-Characteristics:Generally similar to the B-type asteroids, but...
, which means that it is very dark in colouring (darker than soot
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
) with a carbonaceous
Carbonate
In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, . The name may also mean an ester of carbonic acid, an organic compound containing the carbonate group C2....
composition. Like Mathilde
253 Mathilde
253 Mathilde is a main-belt asteroid about 50 km in diameter that was discovered by Johann Palisa in 1885. It has a relatively elliptical orbit that requires more than four years to circle the Sun. This asteroid has an unusually slow rate of rotation, requiring 17.4 days to complete a...
, its density appears to be unusually low, indicating that it may be a loosely-packed rubble pile, not a monolithic object. Eugenia appears to be almost anhydrous
Anhydrous
As a general term, a substance is said to be anhydrous if it contains no water. The way of achieving the anhydrous form differs from one substance to another...
.
Lightcurve analysis indicates that Eugenia's pole most likely points towards ecliptic coordinates
Ecliptic coordinate system
The ecliptic coordinate system is a celestial coordinate system that uses the ecliptic for its fundamental plane. The ecliptic is the path that the sun appears to follow across the celestial sphere over the course of a year. It is also the intersection of the Earth's orbital plane and the celestial...
(β, λ) = (-30°, 124°) with a 10° uncertainty, which gives it an axial tilt
Axial tilt
In astronomy, axial tilt is the angle between an object's rotational axis, and a line perpendicular to its orbital plane...
of 117°. Eugenia's rotation is then retrograde.
Petit-Prince
In November 1998, astronomers at the Canada-France-Hawaii Telescope
Canada-France-Hawaii Telescope
The Canada–France–Hawaii Telescope is located near the summit of Mauna Kea mountain on Hawaii's Big Island at an altitude of 4,204 meters , and is one of the observatories that comprise the Mauna Kea Observatory...
on Mauna Kea
Mauna Kea
Mauna Kea is a volcano on the island of Hawaii. Standing above sea level, its peak is the highest point in the state of Hawaii. However, much of the mountain is under water; when measured from its oceanic base, Mauna Kea is over tall—significantly taller than Mount Everest...
, Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
, discovered a small moon
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
orbiting Eugenia. This was the first time an asteroid moon
Asteroid moon
A minor planet moon is an astronomical body that orbits a minor planet as its natural satellite. It is thought that many asteroids and Kuiper belt objects may possess moons, in some cases quite substantial in size...
had been discovered by a ground-based telescope. The moon is much smaller than Eugenia, about 13 km in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
, and takes five days to complete an orbit around it.
The discoverers chose the name "Petit-Prince" (formally "(45) Eugenia I Petit-Prince"). This name refers to Empress Eugenia's son, the Prince Imperial
Napoléon Eugène, Prince Imperial
Napoléon, Prince Imperial, , Prince Imperial, Fils de France, was the only child of Emperor Napoleon III of France and his Empress consort Eugénie de Montijo...
. However, the discovers also intended an allusion to the children's novella
Novella
A novella is a written, fictional, prose narrative usually longer than a novelette but shorter than a novel. The Science Fiction and Fantasy Writers of America Nebula Awards for science fiction define the novella as having a word count between 17,500 and 40,000...
The Little Prince
The Little Prince
The Little Prince , first published in 1943, is a novella and the most famous work of the French aristocrat writer, poet and pioneering aviator Antoine de Saint-Exupéry ....
by Antoine de Saint-Exupéry
Antoine de Saint-Exupéry
Antoine de Saint-Exupéry , officially Antoine Marie Jean-Baptiste Roger, comte de Saint Exupéry , was a French writer, poet and pioneering aviator. He became a laureate of France's highest literary awards, and in 1939 was the winner of the U.S. National Book Award...
, which is about a young prince who lives on an asteroid.
S/2004 (45) 1
A second, smaller (estimated diameter of 6 km) satellite that orbits closer to Eugenia than Petit-Prince has since been discovered and provisionally named S/2004 (45) 1. It was discovered by analyses of three images acquired in February 2004 from the 8.2 m VLTVery Large Telescope
The Very Large Telescope is a telescope operated by the European Southern Observatory on Cerro Paranal in the Atacama Desert of northern Chile. The VLT consists of four individual telescopes, each with a primary mirror 8.2m across, which are generally used separately but can be used together to...
"Yepun" at the European Southern Observatory
European Southern Observatory
The European Southern Observatory is an intergovernmental research organisation for astronomy, supported by fifteen countries...
(ESO) Cerro Paranal
Cerro Paranal
Cerro Paranal , also known as Paranal Mountain is a mountain in the Atacama desert of northern Chile that is home to the Paranal Observatory. It is famous for hosting the Very Large Telescope and the VLT Survey Telescope. It is located 120 km west of Antofagasta and 80 km north of Taltal,...
, in Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
. The discovery was announced in IAUC 8817, on 7 March 2007 by Franck Marchis
Franck Marchis
Franck Marchis , astronomer and planetary scientist, is best known for his discovery and characterization of multiple asteroids and its study of Io volcanism.The asteroid 6639 Marchis was named in his honor on April 4, 2007....
and his IMCCE collaborators.
See also
- Dactyl and Ida243 Ida243 Ida is an asteroid in the Koronis family of the asteroid belt. It was discovered on 29 September 1884 by Johann Palisa and named after a nymph from Greek mythology. Later telescopic observations categorized Ida as an S-type asteroid, the most numerous type in the inner asteroid belt. On 28...
, another asteroidAsteroidAsteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
and asteroid moonAsteroid moonA minor planet moon is an astronomical body that orbits a minor planet as its natural satellite. It is thought that many asteroids and Kuiper belt objects may possess moons, in some cases quite substantial in size...
system catalogued by astronomers