Bridging the Ultraviolet and Optical Regions: Transformation Equations
  between {\it GALEX} and {\it UBV} Photometric Systems
  We derive transformation equations between GALEX and UBV colours by using the
reliable data of 556 stars. We present two sets of equations; as a function of
(only) luminosity class, and as a function of both luminosity class and
metallicity. The metallicities are provided from the literature, while the
luminosity classes are determined by using the PARSEC mass tracks in this
study. Small colour residuals and high squared correlation coefficients promise
accurate derived colours. The application of the transformation equations to 70
stars with reliable data shows that the metallicity plays an important role in
estimation of more accurate colours.
