511 Davida
511 Davida is a main belt asteroid. It was discovered by R. S. Dugan in 1903. It is one of the largest asteroids, measuring 326km in diameter, and is a C-type asteroid, which means that it is dark in colouring with a carbonate composition.
Davida is one of the few main belt asteroids whose shape has been determined by ground-based visual observation. In 2002, astronomers at the Keck Observatory used the Keck II telescope, which is fitted with adaptive optics to photograph Davida. The image revealed a semi-oblong object with at least two flat facets. Its rotation period is about 4 hours.