Analysis of UBV Photometry of the Near-Contact Binary AK Canis Minoris

As a part of our study of eccentric eclipsing binary candidates, we have obtained complete UBV photoelectric light curves of the neglected system AK Canis Minoris. The observations were taken at Lowell Observatory in 1994 February. Two new epochs of minimum light were determined from these observations. A period study, spanning 33 years, was undertaken, and both improved linear and quadratic ephemerides were obtained. The robust period decrease determined in the quadratic ephemeris may imply magnetic braking arising from the solar-type secondary component. UBV light curves formed from our precision observations are presented. The first synthetic light-curve solution of AK CMi is presented. Our analysis reveals that AK CMi is in a near-contact semidetached configuration with an A3 spectral type primary component and a K2 secondary filling its Roche lobe. Contrary to earlier reports that AK CMi has a displaced secondary eclipse, our secondary eclipse occurs at phase 0.5. (Author)