Star (graph theory)
（重定向自Star graph）
![](/Images/godic/202502/13/Star_network_7.svg4652.png")
![The star graphs S3, S4, S5 and S6.](/Images/godic/202502/13/Star_graphs.svg4652.png")
In graph theory, a star Sk is the complete bipartite graph K1,k: a tree with one internal node and k leaves (but, no internal nodes and k + 1 leaves when k ≤ 1). Alternatively, some authors define Sk to be the tree of order k with maximum diameter 2; in which case a star of k > 2 has k − 1 leaves.