Here Dr. Stanek and collaborators will undertake a systematic study of the most massive stars in the Local Universe, by detecting and observing them in eclipsing binaries in the Milky Way, in Local Group galaxies, and even in some galaxies beyond the Local Group. The strategy involves discovering eclipsing binaries via photometric variability surveys, from which the brightest and thus most massive candidates are selected for spectroscopic follow-up. The goal is to find and measure accurate parameters of the most massive stars in these eclipsing binaries, especially those in nearby galaxies with both high and low abundances of heavy elements. The investigators have already begun monitoring several young Galactic clusters and obtaining follow up spectroscopy of bright eclipsing binaries in Local Group galaxies (LMC, SMC, M31, and M33).
The research program is expected to yield accurate fundamental parameters (notably masses and radii) for dozens of massive stars discovered in a variety of environments, and will provide data with which to test stellar atmosphere models, wind models, stellar evolution models for both single and binary stars as a function of composition and the theoretical predictions on the upper limit of the stellar mass. Additionally, it will provide statistics on early-type contact binaries and the binary fraction, thus constraining massive star formation models, and insight into the evolution of open clusters via runaway OB stars that are binaries. As a side product, many new variable stars will also be discovered. Finally, studying the most massive stars will allow new insights into the progenitors of high-mass X-ray binaries, core-collapse supernovae, the connection between supernovae and gamma-ray bursts, and Population III stars.
A significant part of the proposed work will be carried out by a graduate student and a postdoctoral researcher, providing extensive training in cutting-edge scientific research. Results from this project will be broadly disseminated by publication in peer reviewed journals, conference proceedings, the popular press and the Web. All the gathered data and results will be freely available via a public WWW site, as to provide other workers in this field, as well as astronomy educators, with full access to these legacy-quality data.
