423 Diotima is a one of the largest main-belt asteroids. It is classified as a C-type asteroid and is probably composed of primitive carbonaceous material.
It was discovered by Auguste Charlois on December 7, 1896, in Nice. In the late 1990s, a network of astronomers worldwide gathered lightcurve data that was ultimately used to derive the spin states and shape models of 10 new asteroids, including 423 Diotima. Dunham (2002) used 15 chords and obtained an estimated size of 171 x 138 km.
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