Counts and Colors of Faint Galaxies in the U and R Bands 1

Ground-based counts and colors of faint galaxies in the U and R bands in one eld at high Galactic latitude are presented. Integrated over ux, a total of 1:2 10 5 sources per square degree are found to U = 25:5 mag and 6:3 10 5 sources per square degree to R = 27 mag, with d log N=dm 0:5 in the U band and d log N=dm 0:3 in the R band. Consistent with these number-magnitude curves, sources become bluer with increasing uxes of 73 percent of the 6:3 10 5 sources per square degree suggest that the majority of these also lie at z < 3. These results require an enormous space density of objects in any cosmological model.