Stellar equilibrium in 2+1 dimensions

The hydrostatic equilibrium of a 2+1 dimensional perfect fluid star in asymptotically anti-de Sitter space is discussed. The interior geometry matches the exterior 2+1 black-hole solution. An upper mass limit is found, analogous to Buchdahl's theorem in 3+1, and the possibility of collapse is discussed. The case of a uniform matter density is solved exactly and a new interior solution is presented.