Villanova, Pa. – In a galaxy not so far away, two stars are eclipsing each other--a rare interstellar event. Known as eclipsing binaries, such stars comprise only two percent of known stars. The precise determination of their stellar properties is critical to many branches of astrophysics, from studying the life cycles of stars to determining distances throughout the universe. Andrej Prsa, PhD, associate professor, Astrophysics and Planetary Science, in Villanova University’s College of Liberal Arts and Sciences, has been awarded two grants from the National Science Foundation (NSF) to study these types of stars. The grants, totaling $470,000, will enable Dr. Prsa and his research group to refine and develop models for studying these unique stars.
Studying these stars and their orbiting of potentially habitable planets has been a cornerstone of Dr. Prsa’s work with NASA’s Kepler Mission. Dr. Prsa’s $170,000 Collaborative Research grant, titled “A uniform sample of Kepler eclipsing binaries as benchmark stars to constrain stellar models and evolution at the bottom of the main sequence,” is an extension of a 2012 NASA grant. The research is being conducted in collaboration with Pennsylvania State University.
The research seeks to measure the mass and radius of binary stars with better than three percent precision. It also is meant to characterize the stars’ composition, which will help to inform the potential habitability of orbiting planets. Penn State is analyzing the data spectroscopically, while Villanova is using the model known as PHOEBE (Physics of Eclipsing Binaries), developed by Dr. Prsa to model eclipsing binary stars. It is a tool based on photometric and spectroscopic data that is free to use from a web download.
“Right now the discrepancies are at three to five percent with the current model of PHOEBE,” said Dr. Prsa. “That isn’t good enough. This research will bring uncertainties in our calculations down to one percent.”
For that reason, Dr. Prsa applied for a second NSF grant, which received a $300,000 award. The project, titled “1% accuracy in fundamental stellar parameters? Not without an extensive redesign of eclipsing binary models,” proposes new physics at a new, higher level of precision for measuring eclipsing binaries. It is the next generation of PHOEBE.
Dr. Prsa’s research is being conducted with the help of Villanova undergraduate students, who will assist with testing the models in order to find the best fit. The testing includes using artificial intelligence to run data through the model, which includes tens of millions of binary stars from the GAIA mission and NASA’s Large Synoptic Survey Telescope.
“The analysis of the stars is broken up into separate areas using the neural network, which allows the network to solve equations extremely fast,” noted Dr. Prsa. “All of the algorithms being developed by the neural network and in our research group are applicable to all sciences and mathematics that deal with large data sets.”
“These two NSF grants reflect the high regard in which Dr. Prsa’s research is held, and will help him and his students shed new light on this important area of astrophysics,” said Adele Lindenmeyr, PhD, Dean, Villanova University College of Liberal Arts and Sciences.