1747 Wright, provisional designation , is a stony asteroid and a sizable

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 in ...

, approximately 6 kilometers in diameter. It was discovered on 14 July 1947, by American astronomer Carl Wirtanen at Lick Observatory on Mount Hamilton near San Jose, California. It was named in memory of astronomer William Hammond Wright.

Orbit and classification

''Wright'' orbits the Sun at a distance of 1.5–1.9 AU once every 2 years and 3 months (816 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-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.11 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 reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

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 agains ...

. As 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 mos ...

were taken and no previous identifications were made, ''Wright'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 with its official discovery observation at Mount Hamilton in 1947.

Physical characteristics

Spectral type and mineralogy

In the SMASS taxonomic system, ''Wright'' is an Sl-type, which transitions between the common stony S-type and the less common L-type asteroids. In the

Tholen classification An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiated ...

, this asteroid could not be assigned to a specific type. Its spectrum was unusual and noisy and resembled that of an

A-type asteroid A-type asteroids are relatively uncommon inner-belt asteroids that have a strong, broad 1 μm olivine feature and a very reddish spectrum shortwards of 0.7 μm. They are thought to come from the completely differentiated mantle of an asteroi ...

. In 2012, ''Wright'' was observed in the near-infrared using the SpeX instrument of the NASA Infrared Telescope Facility on Mauna Kea, Hawaii. The spectral measurement indicate that ''Wright'' is not an olivine-rich A-type, but rather similar to the

ordinary chondrite The ordinary chondrites (sometimes called the O chondrites) are a class of stony chondritic meteorites. They are by far the most numerous group, comprising 87% of all finds. Hence, they have been dubbed "ordinary". The ordinary chondrites are t ...

s, with the common H chondrite as the most likely meteorite analogue for the asteroid's composition, as the spectra strongly indicate the presence of rock-forming pyroxenes minerals. The team of astronomers also characterized ''Wright'' as an class asteroid using the Bus–DeMeo taxonomic system.

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite

IRAS The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mo ...

and the Japanese

Akari Akari (ASTRO-F) was an infrared astronomy satellite developed by Japan Aerospace Exploration Agency, in cooperation with institutes of Europe and Korea. It was launched on 21 February 2006, at 21:28 UTC (06:28, 22 February JST) by M-V rocke ...

satellite, the asteroid measures 5.17 and 6.35 kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of 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 that refl ...

of 0.20 and 0.32, respectively. The ''Collaborative Asteroid Lightcurve Link'' agrees with the results obtained by IRAS.

Photometry

In July 2005, a 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 freq ...

of ''Wright'' was obtained by astronomers Reiner Stoss, Jaime Nomen, Salvador Sánchez and

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 ...

at the Mallorca Observatory, Spain. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of 0.61

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 ...

(). In July 2014, another, concurring lightcurve with a period of hours and an amplitude of 0.53 was obtained by

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was a leading English actor in the early years of Britain's Royal National Theatre. He was one of the most respected actors of his generation and was at one time regarded as the natu ...

at the Trojan Station of the Center for Solar System Studies () in Landers, southern California.

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 ''mino ...

was named in memory of American astronomer William Hammond Wright (1871–1959), staff member and later director of the discovering Lick Observatory until 1942. A pioneer in astrophysics, his large, wide-field ''20-inch Carnegie double

astrograph An astrograph (or astrographic camera) is a telescope designed for the sole purpose of astrophotography. Astrographs are mostly used in wide-field astronomical surveys of the sky and for detection of objects such as asteroids, meteors, a ...

'' built for the observatory's proper motion survey ( first light in 1941), was using distant galaxies (" spiral nebulae") as object references. During this survey, many comets and asteroids were discovered as a by-product. The official was published by the Minor Planet Center on 20 February 1976 (). Wright is also honored by the

Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. It became the most popular celestial object in fiction in the late 1800s as the Moon was evidently lifeless. At the time, the pr ...

and lunar craters ''Wright''.