| Abstract | Deep two-color (V and I) CCD photometry of stars in the halos of M31 and M33 is presented. The color-magnitude diagrams show the brightest 2 mag of the giant branches in the two galaxies. The M31 halo giant branch is very broad, indicating a large dispersion in metallicity, and the M33 halo giant branch is much narrower and less metal-rich; quantitative estimates for the mean values of M/H are -0.6 in M31 and -2.2 in M33. Comparisons of the observed brightness of the tips of the giant branches with the calibration of Frogel, Cohen, and Persson (1983) give distance moduli of 24.4 + or - 0.25 for M31 and 24.8 + or - 0.3 for M33. |
