Gravastars and bifurcation in quasistationary accretion
  We investigate the newtonian stationary accretion of a polytropic perfect fluid onto a central body with a hard surface. The selfgravitation of the fluid and its interaction with luminosity is included in the model. We find that for a given luminosity, asymptotic mass and temperature of the fluid there exist two solutions with different cores. 
Edward Malec and Krzysztof Roszkowski