New Light Curves and Orbital Solution for AM Leonis

Abstract

New UBVRI photometry has been obtained for the W UMa eclipsing system AM Leonis. The data have been used to derive nine times of minimum and to construct light curves. The minimum timings show that the system recently had a significant period increase. Modeling of the light curves shows AM Leo to be an overcontact system with a mass ratio of 2.51. Both Rucinski & Duerbeck's absolute magnitude calibration for W UMa stars applied to our photometry and the radial velocity curve combined with our derived parameters indicate a distance near 125 pc, larger than the 77 pc from the Hipparcos parallax.