Oxygen abundances in the most oxygen-rich spiral galaxies

Oxygen abundances in the spiral galaxies expected to be richest in oxygen are estimated. The new abundance determinations are based on the recently discovered ff relation between auroral and nebular oxygen-line fluxes in high-metallicity H II regions. We find that the maximum gas-phase oxygen abundance in the central regions of spiral galaxies is 12+log(O/H) similar to 8.75. This value is significantly lower (by a factor of greater than or similar to 5) than the previously accepted value. The central oxygen abundance in the Milky Way is similar to that in other large spirals.