The Visual Orbit of iota Pegasi

We have determined the visual orbit for the spectroscopic binary iota~Pegasi with interferometric visibility data obtained by the Palomar Testbed Interferometer in 1997. iota~Pegasi is a double-lined binary system whose minimum masses and spectral typing suggests the possibility of eclipses. Our orbital and component diameter determinations do not favor the eclipse hypothesis: the limb-to-limb separation of the two components is 0.151 +/- 0.069 mas at conjunction. Our conclusion that the iota~Peg system does not eclipse is supported by high-precision photometric observations. The physical parameters implied by our visual orbit and the spectroscopic orbit of Fekel and Tomkin (1983) are in good agreement with those inferred by other means. In particular, the orbital parallax of the system is determined to be 86.9 +/- 1.0 mas, and masses of the two components are determined to be 1.326 +/- 0.016 M_sun and 0.819 +/- 0.009 M_sun respectively.