4090 Říšehvězd, provisional designation , is a stony

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 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 7 kilometers in diameter. It was discovered by Czech astronomer

Antonín Mrkos Antonín Mrkos () (27 January 1918, Střemchoví – 29 May 1996, Prague) was a Czechs, Czech astronomer. Biography Mrkos entered the University in Brno in 1938. His studies were interrupted by the onset of World War II, and in 1945 he became ...

Kleť Observatory Kleť Observatory ( cz, Hvězdárna Kleť; obs. code: 046) is an astronomical observatory in the Czech Republic. It is situated in South Bohemia, south of the summit of Mount Kleť, near the town of České Budějovice. Constructed in 1957, t ...

on 2 September 1986. Named for the astronomy journal Říše hvězd, it is known as having had the most

diacritic A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacriti ...

s in its name among all

named minor planets Named may refer to something that has been given a name. Named may also refer to: * named (computing), a widely used DNS server * Naming (parliamentary procedure) * The Named (band), an American industrial metal group In literature: * ''The Na ...

before the naming of

229762 Gǃkúnǁʼhòmdímà 229762 Gǃkúnǁʼhòmdímà (provisional designation ) is a trans-Neptunian object and binary system from the extended scattered disc, located in the outermost region of the Solar System. It was discovered on 19 October 2007 by American astronom ...

Classification and orbit

The

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 ...

orbits the Sun at a distance of 1.9–2.9 AU once every 3 years and 7 months (1,322 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 1 ° 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 ...

. The first observation was made at the U.S.

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owne ...

in 1931, 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 55 years prior to its official discovery.

Physical characteristics

In 2009 and 2014, several 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 ...

s were obtained for this asteroid at the

Palomar Transient Factory The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...

. They gave a concurring

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 ...

between 4.53 and 4.56 hours with a brightness variation between 0.32 and 0.41

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 ...

(). According to the survey carried out by the

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 of 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, ...

, the asteroid measures 7.2 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 ...

of 0.149, while the ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 6.3 kilometers, based on an absolute magnitude of 13.38.

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 ...

was named after the periodically released Czech popular astronomy journal Říše hvězd ("the realm of stars"), which was initially published by the Czech Astronomical Society. Říše hvězd reported discoveries in the fields of astronomy, astrophysics and space exploration and supplied information about the Czech–Slovak astronomical community. The body's name was proposed by

Jana Tichá Jana Tichá (born 1965 in České Budějovice) is a Czech astronomer and discoverer of minor planets. She studied at the University of Economics in Prague and graduated in 1987. In 1992 she was selected for the position of a director of the Kle ...

Miloš Tichý Miloš Tichý (born 1966 in Počátky) is a Czech astronomer. He is a prolific discoverer of asteroids. He also discovered the periodic comet 196P/Tichý. He works together with his ex-wife at Kleť Observatory Kleť Observatory ( cz, Hvězd� ...

and

Zdeněk Moravec Zdeněk Moravec (born 1968) is a Czech astronomer and astrophysicist. Zdeněk Moravec is a graduate from Charles University in Prague. He became a prolific discoverer of minor planets, during his stay at the Kleť Observatory in South Bohemia, ...

. Naming citation was published on 28 August 1996 ().

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:Risehvezd 004090 Discoveries by Antonín Mrkos Named minor planets 19860902

Classification and orbit

Physical characteristics

Naming

See also

References

External links