Discovered by T. Kobayashi MPC designation 7803 Adachi Discovered 4 March 1997 Orbits Sun Discovery site Ōizumi Observatory | Discovery date 4 March 1997 Minor planet category main-belt · (middle) Absolute magnitude 13.1 Asteroid group Asteroid belt | |
Named after Makoto Adachi(amateur astronomer) Alternative names 1997 EW2 · 1973 AA31976 UY17 · 1978 EM11992 CF2 | ||
7803 Adachi, provisional designation 1997 EW2, is an asteroid from the middle region of the asteroid belt. It was discovered by Japanese amateur astronomer Takao Kobayashi at the Ōizumi Observatory in central Japan, on 4 March 1997. Depending on the body's divergent spectral type assessment, it measures between 6 and 10 kilometers in diameter.
The asteroid orbits the Sun at a distance of 2.6–2.9 AU once every 4 years and 8 months (1,697 days). Its orbit has an eccentricity of 0.05 and an inclination of 5° with respect to the ecliptic. 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.
The Collaborative Asteroid Lightcurve Link (CALL) classifies this asteroid as a dark C-type with an assumed standard albedo of 0.057, and calculates a diameter of 10.3 kilometers. However, the body has also been classified as a stony S-type by the large-scale Pan-STARRS survey. This spectral type also agrees with the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), which gave a much higher albedo of 0.25. According to WISE, the asteroid's has a smaller diameter of 6.4 kilometers.
A rotational light-curve of this asteroid was obtained through photometric observations at the U.S. Palomar Transient Factory in August 2013. It showed a period of 7000519660000000000♠5.1966±0.0082 hours with a brightness amplitude of 0.31 in magnitude (U=2).
The minor planet was named after Makoto Adachi (b. 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. Naming citation was published on 6 August 2003 (M.P.C. 49279).