Cepheid color-temperature relations

Using our 1997 work in spectroscopic temperatures, as well as published Cep heid photometry, we derive color-temperature relations for a set of 13 Ceph eids in Galactic clusters. The colors and temperatures used are individual values taken at different phases, rather than mean values averaged over the pulsational. cycle. The observed colors are corrected for both reddening a nd metallicity. The effect of gravity on the colors is small. We find that B-V and V-R are the best colors to use to determine a Cepheid photometric t emperature scale. These color-temperature relations will be useful for futu re Cepheid Baade-Wesselink studies and for abundance analyses of more Galac tic and extragalactic Cepheids.