1310 Villigera, provisional designation , is a stony

asteroid An asteroid is a minor planet of the Solar System#Inner solar system, 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 o ...

and large

Mars-crosser A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for ...

from the innermost 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 ...

, approximately 14 kilometers in diameter. It was discovered on 28 February 1932, by German astronomer

Friedrich Schwassmann Friedrich Karl Arnold Schwassmann (25 March 1870 – 19 January 1964) was a German astronomer and a discoverer of 22 minor planets and 4 comets, who worked at AOP in Potsdam and at Bergedorf Observatory in Hamburg. He was co-discoverer with ...

Bergedorf Observatory Hamburg Observatory (german: Hamburger Sternwarte) is an astronomical observatory located in the Bergedorf borough of the city of Hamburg in northern Germany. It is owned and operated by the University of Hamburg, Germany since 1968, although it ...

in Hamburg, Germany. The asteroid was named after astronomer Walther Villiger.

Orbit and classification

''Villigera'' is a

Mars-crossing asteroid A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for in ...

, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin atmos ...

at 1.666 AU. It orbits the Sun in the inner main-belt at a distance of 1.5–3.2 AU once every 3 years and 8 months (1,352 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 ...

of 0.36 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 21 ° 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 agai ...

. No

precoveries 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 mo ...

were taken, and no prior identifications were made. 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 ...

begins 10 days after its official discovery observation with its first used observation at

Uccle Observatory The Royal Observatory of Belgium (french: link=no, Observatoire Royal de Belgique, nl, Koninklijke Sterrenwacht van België), has been situated in the Uccle municipality of Brussels (Belgium) since 1890. It was first established in Saint-Josse ...

Physical characteristics

''Villigera'' 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 secon ...

on the Tholen taxonomic scheme.

Lightcurves

In October 2001, a first 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 ''Villigera'' was obtained by astronomer Robert Koff at Thornton Observatory () in Colorado. Light curve 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 7.830 hours with a brightness variation of 0.39

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 ...

(). Photometric observations by astronomers

René Roy René Roy may refer to: * René Roy (economist) * René Roy (chemist) * René Roy (astronomer) 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 ...

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 numb ...

and

Pierre Antonini Pierre Antonini is a retired French mathematics professor and amateur astronomer who has discovered several minor planets and two supernovae at his private Observatoire de Bédoin (Bedoin Observatory; observatory code: 132) located at Bédoin, ...

in February 2006, gave a concurring period of 7.834 hours and an amplitude of 0.36 magnitude (). In 2016, a modeled lightcurves using photometric data from various sources, rendered an identical period of 7.830 and a spin axis of (3.0°, 63°) in

ecliptic coordinates The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodi ...

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 2 ...

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 20 ...

mission, ''Villigera'' measures 13.76 kilometers in diameter and its surface has an albedo of 0.245. The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 15.24 kilometers, with an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse logarithmic astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent magnitude that the object would have if it we ...

of 11.45. Based on a generic magnitude-to-diameter conversion, ''Villigera'' measures between 13 and 30 kilometers for an albedo in the range of 0.05 to 0.25. This makes ''Villigera'' one of the largest mid-sized

s comparable with 1065 Amundsenia (9.75 km),

1139 Atami 1139 Atami, provisional designation , is a stony asteroid and sizable Mars-crosser, as well as a synchronous binary system near the innermost region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 1 December 1929 ...

(9.35 km), 1474 Beira (8.73 km), 1011 Laodamia (7.5 km), 1727 Mette (est. 9 km), 1131 Porzia (7 km),

1235 Schorria 1235 Schorria ('' prov. designation:'' ), is a Hungaria asteroid, sizable Mars-crosser, and exceptionally slow rotator from the inner region of the asteroid belt. The carbonaceous C-type asteroid has an outstandingly long rotation period of ...

(est. 9 km), 985 Rosina (8.18 km) and

1468 Zomba 1468 Zomba, provisional designation , is a stony asteroid and large Mars-crosser near the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. Discovered by Cyril Jackson at Johannesburg Observatory in 1938, the asteroi ...

(7 km), but smaller than the largest members of this dynamical group, namely,

132 Aethra Aethra (minor planet designation: 132 Aethra) is a metallic asteroid and Mars-crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter. It was discovered by James Craig Watson in 1873 and is the ...

, 323 Brucia, 1508 Kemi, 2204 Lyyli and 512 Taurinensis, which are all larger than 20 kilometers in diameter.

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 '' ...

was named in honour of Swiss astronomer Walther Villiger (1872–1938), who himself discovered the main-belt asteroid 428 Monachia at Munich in 1897. The official naming citation was also mentioned in ''

The Names of the Minor Planets Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinn ...

'' by

Paul Herget Paul Herget (January 30, 1908 – August 27, 1981) was an American astronomer and director of the Cincinnati Observatory, who established the Minor Planet Center after World War II. Career Herget taught astronomy at the University of Cincinn ...

in 1955 ().

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Villigera 001310 Discoveries by Friedrich Karl Arnold Schwassmann Named minor planets 001310 19320228