Surface Photometry of Pure Disk Galaxies

Surface photometry from U.K.S.T.U. plates in U, BJ and RF is presented for the three Sculptor Group galaxies NGC 7793, NGC 247 and NGC 300. Their photometric parameters are derived and compared to those of M33. Our color maps are used to sort out the data into blue and red pixels where the blue pixels profiles are expected to be rather irregular, representative of the clumpy locations of areas of recent star formation while the red pixels profiles should approximate the smoother distribution of the old disk population.