It is the biggest of the class of dark C-type asteroids with a carbonaceous surface that are dominant in the farther part main belt, which lies beyond the Kirkwood gap at 2.82 AU, and is also the biggest body in this region. Its dark surface and bigger than average distance from the Sun makes it very dim for such a big asteroid when seen from Earth. In fact it is the third dimmest of the first twenty-three asteroids discovered, with only 13 Egeria and the quite small 17 Thetis having lower mean opposition magnitudes.