We derive the basic properties of seven Galactic open clusters containing Cepheids and construct their period-luminosity ( P-L ) relations .
For our cluster main-sequence fitting we extend previous Hyades-based empirical color-temperature corrections to hotter stars using the Pleiades as a template .
We use BVI _ { C } JHK _ { s } data to test the reddening law and include metallicity effects to perform a more comprehensive study for our clusters than prior efforts .
The ratio of total to selective extinction R _ { V } that we derive is consistent with expectations .
Assuming the LMC P-L slopes , we find \langle M _ { V } \rangle = -3.93 \pm 0.07 { ( statistical ) } \pm 0.14 { ( % systematic ) } for 10-day period Cepheids , which is generally fainter than those in previous studies .
Our results are consistent with recent HST and Hipparcos parallax studies when using the Wesenheit magnitudes W ( VI ) .
Uncertainties in reddening and metallicity are the major remaining sources of error in the V -band P-L relation , but a higher precision could be obtained with deeper optical and near-infrared cluster photometry .
We derive distances to NGC 4258 , the LMC , and M33 of ( m - M ) _ { 0 } = 29.28 \pm 0.10 , 18.34 \pm 0.06 , and 24.55 \pm 0.28 , respectively , with an additional systematic error of 0.16 mag in the P-L relations .
The distance to NGC 4258 is in good agreement with the geometric distance derived from water masers [ \Delta ( m - M ) _ { 0 } = 0.01 \pm 0.24 ] , our value for M33 is less consistent with the distance from an eclipsing binary [ \Delta ( m - M ) _ { 0 } = 0.37 \pm 0.34 ] , and our LMC distance is moderately shorter than the adopted distance in the HST Key Project , which formally implies an increase in the Hubble constant of 7 \% \pm 8 \% .