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M. B. Lacorte (Rutgers University), W. V. Van Hamme (Florida International University)
Light and radial velocity curves solutions for the eclipsing and spectroscopic binary RU Ursae Minoris are presented. The system is found to be semi-detached with the cooler (less massive) star filling its Roche lobe. The primary (more massive) star fills nearly 94% (by radius) of its limiting lobe. The system's absolute dimensions are determined. Given the primary component's location near the bottom of the instability strip in the H-R diagram, the possibility of intrinsic variability of this star is discussed. The residual light curve shows a small amplitude (\approx 0\fm0012) oscillation with 28 minutes as the most likely period. A Lomb-Scargle periodogram does not rule out the presence of other periods, all of which are characteristic of \delta Scuti variable stars. Given the primary component's mass, radius and effective temperature (2.55\,M\odot, 1.85\,R\odot and 7200 K), a pulsational period of 28 minutes corresponds to the sixth harmonic of the radial pulsation mode. MBL acknowledges support from the Southeastern Association for Research in Astronomy (SARA) Summer Internship Program, sponsored by the National Science Foundation Research Experiences for Undergraduates program (NSF grant AST-9423922).