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Long baseline interferometry is now able to resolve the pulsational changes of the angular diameters of a significant number of Cepheids in the solar neighborhood. This allows us to apply a new version of the Baade-Wesselink method to measure their distances, for which we do not need to estimate the star's temperature. Using this method and angular diameter measurements from the VLT Interferometer, we derived the distances to four nearby Cepheids. For three additional stars, we obtained average values of their angular diameters and we estimated their distances from previously published values of their linear sizes. Based on these new measurements and already existing data, we derived new calibrations of the Period-Luminosity and Period-Radius relations. Additionally, we obtained high precision surface brightness-color relations based solely on interferometric angular diameter measurements on Cepheids and BVRIJHK magnitudes. We finally discuss the prospects of the direct distance measurements of Cepheids. [ABSTRACT FROM AUTHOR]

We present the first direct distance determination to a detached eclipsing binary in M33, which was found by the DIRECT Project. Located in the OB 66 association, it was one of the most suitable detached eclipsing binaries found by DIRECT for distance determination, given its 4.8938 day period. We obtained follow-up BV photometry and spectroscopy from which we determined the parameters of the system. It contains two O7 main sequence stars with masses of 33.4 ± 3.5 M⊙ and 30.0 ± 3.3 M⊙ and radii of 12.3 ± 0.4 R⊙ and 8.8 ± 0.3 R⊙, respectively. We derive temperatures of 37000 ± 1500 K and 36000 ± 1500 K and determine the reddening E(B − V) = 0.14 ± 0.03. Using HST photometry for flux calibration in the V band, we obtain a preliminary distance modulus of 24.87 ± 0.16 mag (942 ± 73 kpc). The photometry and thus distance is subject to revision in the final paper. [ABSTRACT FROM AUTHOR]