Near-infrared variant of the Barnes-Evans method for finding Cepheid distances calibrated with high-precision angular diameters

The advantages of a near-infrared variant of the Barnes-Evans method for estimating distances to Cepheid variables are described and quantified. A surface brightness-color relation for K photometry and the (V - K)0 color index is established using modern, high-precision angular diameters from optical interferometers. Applied to data for the galactic (cluster) Cepheid U Sgr, this method yields a distance of 0.660±0.024 kpc and a true distance modulus of 9.10±0.07 mag. This estimate compares with the true distance modulus of 9.37±0.22 mag estimated by Gieren et al. [ApJ, 418, 135 (1993)] using the classical Barnes-Evans technique. The possibility of estimating distances of LMC and SMC Cepheids directly - without intermediate steps - is discussed. The feasibility of determining the distance of M31 or M33 using this technique is examined and is probably within the reach of 8 m class telescopes.