AAVSO: American Association of Variable Star Observers

Light Curve Asymmetries in Three Short Period Eclipsing Binary Stars

Volume 48 number 1 (2020)

Download this article (pdf)

Gage Hahs
Truman State University, 100 E. Normal Street, Kirksville, Mo, 63501, gokhale@truman.edu
Charlyn Ortmann
Truman State University, 100 E. Normal Street, Kirksville, Mo, 63501, gokhale@truman.edu
Vayujeet Gokhale
Truman State University, 100 E. Normal Street, Kirksville, Mo, 63501, gokhale@truman.edu

Abstract

We present light curve analysis of three variable stars, NSVS 10384295 (P = 0.297899 d), NSVS 7347726 (P = 0.43394 d), and NSVS 13251721 (P = 0.23340 d), using data collected at the 31-inch NURO telescope at the Lowell Observatory in Flagstaff, Arizona, in three filters: Bessell B, V, and R. We quantify the asymmetries in these systems by generating a twelve-term Fourier fit and using the resulting Fourier coefficients to calculate ΔI (the difference in the heights of the primary and secondary maxima), the “Light Curve Asymmetry” (LCA), and the “O’Connell Effect Ratio” (OER). Our analysis shows that of the three systems studied, NSVS 13251721 has the most asymmetric light curve, and that NSVS 7347726 has the most symmetric light curve. We also observe that for all three systems, the asymmetries are most pronounced in the B filter, and the least in the R filter. Additionally, we use the Fourier coefficients to confirm NSVS 10384295 and NSVS 13251721 as W UMa type systems, and NSVS 7347726 to be a β Lyrae type system.