AAVSO: American Association of Variable Star Observers

Characterizing the O’Connell Effect in Kepler Eclipsing Binaries (Abstract)

Volume 49 number 1 (2021)

Matthew Knote
Department of Aerospace, Physics, and Space Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901; mknote2015@my.fit.edu

Abstract

(Abstract only) The O’Connell effect—the presence of unequal maxima in eclipsing binary light curves—is a poorly understood phenomenon that has been recognized for over a century. Several ideas have been proposed to explain it, including chromospheric spots, effects of mass transfer, or circumstellar material, but the exact cause of the effect nevertheless remains unresolved. The Kepler mission observed nearly 3,000 eclipsing binaries, of which my analysis shows that over 200 show a significant O’Connell effect. Our goal is to analyze and characterize this sample of systems as a prelude to future projects looking to determine the physical cause of the phenomenon. I now present the results we have obtained thus far, such as a correlation between the O’Connell effect size and eclipse depth. I will also discuss some interesting classes of systems we have discovered, including systems with considerable temporal variation and systems with asymmetric minima that warrant further observations.