RESOLVED COMPANIONS OF CLASSICAL CEPHEIDS

Images of classical Cepheids with relatively close bright companions have been obtained. The purpose is twofold. The first is to measure V and B - V of the companions in order to determine the effect of the companion on Cepheid photometry. The second is to investigate whether the companions are likely to be physically associated with the Cepheids. Nine of the 13 companions are very blue [assuming the E(B - V) from the Cepheid], which is strong evidence that they are young stars associated with the Cepheids. None of the blue companions have a significantly larger projected separation from the Cepheids than Abt's 42 000 AU limit for the widest B star binaries, which is the same order of magnitude as the 0.1 pc maximum projected separation from a number of other studies.