9526034 Heacox The objective of the research to be carried is to deduce reliable observational constraints on the theories of the formation of binary star systems. There is very little currently known about the overall binary stellar system characteristics which are relevant to their formation. In particular, we do not know whether the masses of the secondary stars in binary systems are distributed in the same manner as those of primary and single stars. There is almost no knowledge of the values and ranges of the orbital angular momenta values characterizing binary stars. This last issue is particularly important, since binary star orbits may act as the repositories of the original angular momentum of the dense cloud cores from which the systems form, thus aiding in the formation of the central concentration of material necessary for star formation. A reliable estimate of the joint distribution of semi-major axes and secondary/primary mass ratios, characterizing binaries as a whole, is needed to correct these deficiencies. The method for deducing this distribution is that of statistical modeling, wherein the distributions of the desired intrinsic characteristics (semi-major axes, mass ratios) are related to those of the observable quantities (orbital periods, velocities, etc.) in a deterministic manner that preserves all the information in the data. Mathematically rigorous methods of developing such models will be used, as well as the use of the means of their statistical inversion, to infer the desired intrinsic distribution from that of the observables. Model outlines will be given for all observational binary star types (spectroscopic, visible, etc.). These models will be used with the data, from recent and future observationally unbiased surveys of binary star systems, to determine the joint distributions of semi-major axes and mass rat ios characterizing binary star systems of homogeneous primary types. These distributions of characteristics may then be used to directly determine the secondary mass function and distribution of orbital angular momentum values (and other dynamic characteristics) characterizing binary star systems as a whole. The resulting distributions will constitute the first truly meaningful observational constraints on the dominant mode of star formation (most stars are members of binary systems). This will help to determine the extent to which any of the current theories of binary star formation are correct, and advance our understanding of the process of star formation in general. ***
