On a class of graphs without 3-stars

M. Numata described edge regular graphs without 3-stars. All $\mu$-subgraphs of these graphs are regular of the same valency. We prove that a connected graph without 3-stars all of whose $\mu$- subgraphs are regular of valency $\alpha>0$ is either a triangular graph, or the Shläfli graph, or the icosahedron graph.