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An Analysis of Eclipsing Binary Systems Exhibiting the O'Connell Effect

POSTER

Abstract

Over half of the stars in our galaxy are binary stars, which consist of two stars orbiting their common center of mass. Eclipsing binaries are variable stars that appear to overlap each other from the Earth's vantage point. One complete cycle includes two eclipses: the primary eclipse, in which the brighter star is obscured, and the secondary eclipse, in which the fainter star is obscured. Some binaries also have a difference in their maxima due to the O'Connell effect, a yet unexplained phenomenon. The O'Connell effect is counterintuitive, as the orientation of adjacent stars should not affect their intensity. In our research, we analyzed the light curves of several beta Lyrae and W Ursa Majoris type eclipsing binaries that exhibit the O'Connell effect. Using the program VSTAR and Excel's Solver tool, we obtained a Fourier fit for their light curves and estimates for the difference in maximum brightness. We will present raw light curves for these binaries along with calculated fits and differences in magnitude. A comparison between our new data and previous observations from the literature can reveal how the orbital period and difference in maximum brightness change over time.

Authors

  • Allison Helferty

    Juniata College

  • Kristin Rabosky

    Middle Tennessee State University, University of Alabama Tuscaloosa, Swarthmore College, CT Clinical Innovation Center, Department of Radiology, Mayo Clinic, Rochester, MN, Bard College, Wright State University, University of Michigan, University of Hawai'i-Manoa, Rice University, University of Alaska Fairbanks, University of Utah, South Dakota School of Mines and Technology, Furman University, University of Notre Dame, Theoretical Physics Division, Institute of High Energy Physics, the Chinese Academy of Sciences, Peng Huanwu Center for Fundamental Theory, University of Science and Technology China, University of Cambridge, University of Kansas, SLAC National Accelerator Laboratory, Planetary Science Institute, Iowa State University, College of Idaho, University of Washington, Bothell, Ottawa Hills High School, Case Western Reserve University, Yale University and Strasbourg Astronomical Observatory, Yale University, Korea Astronomy and Space Science Institute, NOIRLab, Purdue University, Korea Instotute for Advanced Study, Perimeter Institute, Rutgers University, University of Maryland, Juniata College, Columbia University, City University of New York / American Museum of Natural History, Columbia University / American Museum of Natural History, Morehead State University, Hofstra University, Occidental College, Georgia Institute of Technology, School of Physics and Astronomy, University of Minnesota, The Oskar Klein Centre, Department of Astronomy, University of Mississippi, Stanford/KIPAC/SLAC, University of Connecticut, Kansas State University, Vassar College, Penn State, Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Department of Physics, Worcester Polytechnic Institute, Clark University, University of Illinois at Urbana-Champaign, Rhodes College, Rensselaer Polytechnic Institute, Harvard University, Cornell University, Air Force Research Lab, Wright-Patterson AFB, Ohio 45433, Air Force Research Lab, Wright-Patterson AFB, Ohio 45433 & UES, Inc., 4401 Dayton-Xenia Rd, Dayton, OH 45432, Department of Physics, University of Dayton, Dayton Ohio & Air Force Research Lab, Wright-Patterson AFB, Ohio 45433, Los Alamos National Laboratory, Utah State University, Ramapo College of NJ, Brookhaven National Laboratory, Research Center of Topological Functional Materials and Henan Key Laboratory of Photovoltaic Materials, Henan Univers., Brookhaven National Laboratory, Montclair State University, Weber State University