BINARY STAR ORBITS FROM SPECKLE INTERFEROMETRY .9. THE NEARBY SOLAR-TYPE SPECKLE-SPECTROSCOPIC BINARY FIN-347-AA

Visual, interferometric, and spectroscopic observations are presented for the nearby solar-type binary Fin 347 Aa. In a new solution combini ng both astrometric and spectroscopic data the orbital period is found to be 987.9 days or 2.7048 years, the semimajor axis 2.42 AU or 0''.1 16, the eccentricity 0.429, and the inclination 124 degrees.31. The ma sses and luminosities for this pair of G8 V stars are 1.015+/-0.038 M. , 0.933+/-0.039 M., 0.64+/-0.06 L., and 0.62+/-0.06 L., respectively. The orbital parallax of 0''.0480+/-0''.0011 gives a distance of 20.8 4 +/-0.47 pc. The small formal errors on all orbital elements leads to s mall errors for the masses and luminosities. The stars are found to be slightly over-massive and under-luminous for their spectral classific ations. (C) 1996 American Astronomical Society.