The metallicities of UM 151, UM 408 and A 1228+12 revisited

We present the results of new spectrophotometry and heavy element abundance determinations for 3 dwarf galaxies UM 151, UM 408 and A 1228+12 (RMB 132). These galaxies have been claimed in the literature to have very low metallicities, corresponding to log(O/H) + 12 less than or equal to 7.65, that are in the metallicity range of some candidate local young galaxies. We present higher S/N data for these three galaxies. UM 151 and UM 408 have significantly larger metallicities: log(O/H) + 12 = 8.5 and 7.93, respectively. For A 1228+12 our new log(O/H) + 12 = 7.73 is close to that recalculated from earlier data (7.68). Thus, the rederived metallicities allow us to remove these objects from the list of galaxies with Z. less than or similar to 1/20 Z.