Orbital and Stellar Parameters of Omicron Leonis from Spectroscopy and Interferometry

We present a three-dimensional solution for the orbit of the double star Omicron Leonis, based on new photoelectric radial velocity data mainly from the Observatoire de Haute-Provence and on interferometric data obtained with the Navy Prototype Optical Interferometer, the Mark III Stellar Interferometer, and the Palomar Testbed Interferometer. Omicron Leo's primary is a giant of type F9 and the secondary is an A5m dwarf, for which we derive masses of 2.12 ± 0.01 M ⊙ and 1.87 ± 0.01 M ⊙ , respectively. The distance to the binary is determined to be 41.4 ± 0.1 pc. Combining the distance with the measured apparent magnitudes and color differences between the components yields luminosities of 39.4±2.4 L ⊙ and 15.4 ± 1.0 L ⊙ for primary and secondary, respectively. Data from the Palomar Testbed Interferometer taken at 2.2 μm are used to constrain the photometry in the infrared.