A well-defined Hirayama family of asteroids in the outer region of the main asteroid belt at a mean distance of 2.87 AU from the Sun. The members are mainly S-class asteroids with very similar colours, spectra, and albedos. They are believed to have originated in the break-up of a highly homogeneous parent body, presumably of S class. The largest family members are (208) Lacrimosa, diameter 41 km, and (167) Urda, diameter 40 km. Ida is also a member. The family is named after (158) Koronis, an S-class asteroid of diameter 35 km, discovered in 1876 by the German astronomer Victor Carl Knorre (1840–1919). The orbit of Koronis has a semimajor axis of 2.872 AU, period 4.87 years, perihelion 2.71 AU, aphelion 3.03 AU, and inclination 1°.0.
Subjects: Astronomy and Astrophysics.