The quality of the science of astronomy depends, like all the natural sciences, on the acquisition of fundamental data about the objects of its concern. Three of such fundamental data in astronomy are the masses, radii, and luminosities of stars. These data vary greatly with stellar types. So do the problems associated with their acquisition. The Principal Investigator (PI) proposes to continue with his current NSF-funded research program of obtaining mass, radius, and luminosity data of stars by measuring the velocity variations of eclipsing binary stars. In the past, the PI focused on early type main sequence stars, which are relatively bright and, hence, easy to observe. In the present proposal, he intends to focus on binary systems with G- and K-type main-sequence stars, for which relatively few reliable results have been obtained to date because of these stars' faintness. To overcome the problems associated with faintness, the PI will be using the recently developed Hamilton Echelle Spectrometer and a charge-coupled device (CCD) of the Lick Observatory. In addition to the project just described, the PI will be alert to "targets of opportunity" and search for faint secondary components of bright evolved B stars.
