The M dwarf problem: Fe and Ti abundances in a volume-limited sample of M dwarf stars

We report iron and titanium abundance measurements from high resolution spectrain a volume-limited sample of 106 M0 and M0.5 dwarf stars. The sample includesstars north of the celestial equator and closer than 29 parsecs. The results imply thatthere is an M dwarf problem similar to the previously known G dwarf problem, in thatthe fraction of low-metallicity M dwarfs is not large enough to fit simple closed-boxmodels of Galactic chemical evolution. This volume-limited sample avoids many of thestatistical uncertainties present in a previous study using a brightness-limited sampleof M dwarf stars