THE FIRST IMAGES FROM AN OPTICAL APERTURE SYNTHESIS ARRAY - MAPPING OF CAPELLA WITH COAST AT 2 EPOCHS

We present the first aperture synthesis maps obtained using closure ph ase techniques with a separated-element optical interferometer. Maps o f the double-lined spectroscopic binary Capella (alpha Aurigae) were o btained at 830 nm with three elements of the Cambridge Optical Apertur e Synthesis Telescope (COAST) in September 1995. These maps show clear ly the milliarcsecond orbital motion of the system over a 15 day inter val. The image quality is comparable to that of VLBI images obtained u sing similarly sparse radio synthesis arrays, and the location and mot ion of the binary components are in excellent agreement with the predi ctions of the latest set of orbital elements. These data demonstrate f or the first time the feasibility of operating long-baseline optical/n ear-infrared interferometers for high-dynamic range high-resolution im aging.