9000 Hal
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9000 Hal, provisional designation Template:Mp, is a stony background asteroid and slow rotator from the inner regions of the asteroid belt, approximately Script error: No such module "convert". in diameter. It was discovered on 3 May 1981, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station near Flagstaff, Arizona, in the United States.[1] The likely elongated S-type asteroid has an exceptionally long rotation period of 908 hours.[2] It was named after the fictional supercomputer HAL 9000, featured in the 1968 film 2001: A Space Odyssey.[1]
Orbit and classification
Hal is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[3] Based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the Flora family (402Script error: No such module "Check for unknown parameters".), a giant asteroid family and the largest family of stony asteroids in the main-belt.[2]
Hal orbits the Sun in the inner asteroid belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,216 days; semi-major axis of 2.23 AU). Its orbit has an eccentricity of 0.21 and an inclination of 6° with respect to the ecliptic.[4] The asteroid was first observed as Template:Mp at Crimea–Nauchnij in November 1975. The body's observation arc begins with its official discovery observation at Anderson Mesa in May 1981.[1]
Physical characteristics
Hal is an assumed stony S-type asteroid, based on the Collaborative Asteroid Lightcurve LinkTemplate:'s (CALL) classification into the Flora family.[2]
Rotation period
In August 2008, a rotational lightcurve of Hal was obtained from photometric observations by Slovak astronomers Adrián Galád, Jozef Világi, Leonard Kornoš and Štefan Gajdoš at Modra Observatory.[5] Lightcurve analysis gave an exceptionally long rotation period of 908 hours with a high brightness variation of 0.9 magnitude (U=2+Script error: No such module "Check for unknown parameters".). This makes Hal one of the slowest rotators known to exist. In addition, the body's high brightness amplitude is indicative of a non-spherical shape.
An alternative measurement by French amateur astronomers Pierre Antonini and René Roy gave a much shorter period of 22.68 hours.[6] The result, however, is considered of poor quality by CALL (U=1Script error: No such module "Check for unknown parameters".).[2]
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Hal measures between 3.61 and 4.134 kilometers in diameter and its surface has an albedo between 0.26 and 0.375.[7][8][9] CALL assumes an albedo of 0.24 – derived from 8 Flora, the Flora family's parent body – and calculates a diameter of 4.11 kilometers based on an absolute magnitude of 14.1.[2]
Naming
This minor planet was named after the fictional and homicidal supercomputer HAL 9000, featured in both Arthur C. Clarke's novel and Stanley Kubrick's film 2001: A Space Odyssey (1968).[1] HAL stands for Heuristically programmed Algorithmic computer. It is one of the best-known artificial intelligence characters in modern movies. The official naming citation was published by the Minor Planet Center on 4 May 1999 (M.P.C. 34628Script error: No such module "Check for unknown parameters".).[10] The asteroid 4923 Clarke and 10221 Kubrick were named after the writer and film director, respectively.
References
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External links
- Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
- Template:AstDys
- Template:PAGENAMEBASE at the JPL Small-Body DatabaseTemplate:EditAtWikidata
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