|
7803 Adachi
7803 Adachi, provisional designation 1997 EW2, is a stony Agnia asteroid from the middle region of the asteroid belt, approximately 6.4 kilometers (4 miles) in diameter. The asteroid was discovered on 4 March 1997, by Japanese amateur astronomer Takao Kobayashi at the Ōizumi Observatory in central Japan. It was named for Japanese amateur astronomer Makoto Adachi.[1] The S-type asteroid has a rotation period of 5.2 hours.[6] Orbit and classificationAdachi is a member of the Agnia family (514),[3][9] a very large family of stony asteroids with more than 2000 known members.[10] They most likely formed from the breakup of a basalt object, which in turn was spawned from a larger parent body that underwent igneous differentiation.[9] The family's parent body and namesake is the asteroid 847 Agnia.[10] It orbits the Sun in the central asteroid belt at a distance of 2.6–2.9 AU once every 4 years and 8 months (1,698 days; semi-major axis of 2.79 AU). Its orbit has an eccentricity of 0.05 and an inclination of 5° with respect to the ecliptic.[2] The first precovery was taken at the U.S. Palomar Observatory in 1953, extending the asteroid's observation arc by 44 years prior to it discovery.[1] Physical characteristicsAdachi has been characterized as a stony S-type asteroid by Pan-STARRS photometric survey,[8] which agrees with the Agnia family's overall spectral type.[10] : 23 Diameter and albedoAccording to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Adachi measures 6.359 kilometers in diameter and its surface has an albedo between 0.251 and 0.2513.[4][5] The Collaborative Asteroid Lightcurve Link assumes a generic, carbonaceous albedo of 0.057 for all minor planets with a semi-major axis of more than 2.7 AU, and consequently calculates a larger diameter of 10.31 kilometers using an absolute magnitude of 13.66.[6] Rotation periodIn August 2013, a rotational lightcurve of Adachi was obtained through photometric observations at the Palomar Transient Factory in California. It showed a period of 5.1966 hours with a brightness variation of 0.31 magnitude (U=2).[7] NamingThis minor planet was named after Makoto Adachi (born 1953), Japanese amateur astronomer and elementary school teacher from Kyoto. He is the director of the Oriental Astronomical Association and a long-time direct observer of the Solar System's planets, especially Jupiter.[1] The approved naming citation was published by the Minor Planet Center on 6 August 2003 (M.P.C. 49279).[11] References
External links
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Portal di Ensiklopedia Dunia
