On the circular chromatic number of circular partitionable graphs

This article studies the circular chromatic number of a class of circular partitionable graphs. We prove that an infinite family of circular partitionable graphs G has $\chi_ c (G) = \chi(G)$ . A consequence of this result is that we obtain an infinite family of graphs G with the rare property that the deletion of each vertex decreases its circular chromatic number by exactly 1. © 2006 Wiley Periodicals, Inc. J Graph Theory