  We give circularly symmetric solutions for null fluid collapse in
2+1-dimensional Einstein gravity with a cosmological constant. The fluid
pressure $P$ and energy density $\rho$ are related by $P=k\rho$ $(k\le 1)$. The
long time limit of the solutions are black holes whose horizon structures
depend on the value of $k$. The $k=1$ solution is the
Banados-Teitelboim-Zanelli black hole metric in the long time static limit,
while the $k<1$ solutions give other, `hairy' black hole metrics in this limit.

General Relativity and Quantum Cosmology;High Energy Physics - Theory