Binary star differential photometry using the adaptive optics system at Mount Wilson Observatory

We present photometric and astrometric results for 36 binary systems observ ed with the natural guide star adaptive optics system of the Mount Wilson I nstitute on the 100 inch (2.5 m) Hooker Telescope. The measurements consist of differential photometry in U, B, V, R, and I filters along with astrome try of the relative positions of system components. Magnitude differences w ere combined with absolute photometry found in the literature of the combin ed light for systems to obtain apparent magnitudes for the individual compo nents at standard bandpasses, which in turn led to color determinations and spectral types. The combination of these results with Hipparcos parallax m easurements yielded absolute magnitudes and allowed us to plot the componen ts on an H-R diagram. To further examine the reliability and self-consisten cy of these data, we also estimated system masses from the spectral types.