Fundamental Properties of Low Mass Stars in Eclipsing Binaries

San Diego State University Foundation, San Diego CA

Investigators

Abstract

Dr. Orosz will undertake the observation and modeling of a wide variety of close binary systems using in large part telescopes at San Diego State University's Mount Laguna Observatory. Binary stars offer the best opportunity for accurate measurements of the radii and masses of stars, measurements essential to verify stellar evolution theory and to determine the properties of other diverse objects such as white dwarfs, neutron stars, black holes, and extra-solar planets. Here, accurate physical parameters for a wide variety of close binary systems will be determined, including main sequence stars and black holes. A specific goal of this project will be to measure accurate masses and radii for low-mass main sequence stars in order to provide needed constraints on evolutionary models for the lower main sequence (namely the mass-radius relation). This program builds upon recent advances in computer models for binary systems made by Dr. Orosz, most notably the incorporation of specific intensities from model atmosphere computations into a light curve synthesis code and a fitting code based on a genetic algorithm. It has been shown that in some cases the observed light curves can be reproduced much better with these tools, and that the resulting masses and radii of the component stars can be significantly different from what was previously thought. This project also makes use of NSF-funded improvements to the Mount Laguna Observatory, including a completed high-speed Internet connection between San Diego State University and the observatory, substantial upgrades to the existing 1-meter telescope at the observatory, and a robotic 1-meter telescope that will be constructed using new mirror technology. It is expected that fundamental parameters will be found for a large number of binary systems, with a broad impact across diverse areas of astrophysics. The modeling code will be made publicly available, to the benefit of the wider astronomical community. This research will involve advanced San Diego State undergraduate students, graduate students working on Master's Theses, and undergraduate students participating in the NSF-funded Research Experiences for Undergraduates program at San Diego State. Dr. Orosz will also discuss his research in his classes, and to the wider community through outreach events on campus and at the Mount Laguna Observatory.