EXACT-SOLUTIONS FOR NULL FLUID COLLAPSE

Exact nonstatic spherically symmetric solutions of the Einstein equati ons for a null fluid source with pressure P and density rho related by P=k rho(a) are given. The a=1 metrics are asymptotically flat for 1/2 <k less than or equal to 1 and cosmological for 0<k<1/2. The k=1 metri c is the known charged Vaidya solution. In general the metrics have mu ltiple apparent horizons. In the long time limit, the asymptotically f lat metrics are hairy black hole solutions that ''fall between'' the S chwarzschild and Reissner-Nordstrom metrics.