Improved u′g′r′i′z′ to UBVRCIC Transformation Equations for Main-Sequence Stars

We report improved transformation equations between the u′g′r′i′z′ and UBVRCIC photometric systems. Although the details of the transformations depend on luminosity class, we find a typical rms scatter on the order of 0.001 mag if the sample is limited to main-sequence stars. Furthermore, we find that an accurate transformation requires complex, multicolor dependencies for the bluer bandpasses. Results for giant stars will be reported in a subsequent paper.