674 Rachele is a

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 ...

orbiting the Sun. It was discovered by Wilhelm Lorenz on 28 October 1908 in Heidelberg, and was named by orbit computer Emilio Bianchi after his wife. This is classified as an

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 ...

, indicating a stony composition. Measurements made using the adaptive optics system at the

W. M. Keck Observatory The W. M. Keck Observatory is an astronomical observatory with two telescopes at an elevation of 4,145 meters (13,600 ft) near the summit of Mauna Kea in the U.S. state of Hawaii. Both telescopes have aperture primary mirrors, and when comp ...

give a size estimate of 89 km. It has a size ratio of 1.08 between the major and minor axes. By comparison, measurements reported in 1998 from the

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 ...

observatory give a similar size of 97 km and a ratio of 1.15.

References

External links

* * Background asteroids Rachele Rachele Rachele S-type asteroids (Tholen) S-type asteroids (SMASS) 19081028 {{beltasteroid-stub