The notion of the star chromatic number of a graph is a generalization of the chromaticnumber. In this paper. we calculate the star chromatic numbers of three infinite families of planargraphs. The first two families are derived from a 3-or 5-wheel by subdivisions. their star chromaticnumbers being 2+2/(2n + 1). 2+3/(3n + 1)and 2+3/ (3n - 1), respectively. The third family of planargraphs are derived from n odd wheels by Hajos construction with star chromatic numbers 3 + 1/n.which is a generalization of one resnlt of Gao et al.
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