he star graph S_n of order n, sometimes simply known as an "n-star" (Harary 1994, pp. 17-18; Pemmaraju and Skiena 2003, p. 248; Tutte 2005, p. 23), is a tree on n nodes with one node having vertex degree n-1 and the other n-1 having vertex degree 1. The star graph S_n is therefore isomorphic to the complete bipartite graph K_(1,n-1)