Keck interferometer update

The Keck Interferometer combines the two 10 m Keck telescopes for high sensitivity near-infrared fringe visibility measurements, nulling interferometry at 10 mum to measure the quantity of exozodiacal emission around nearby stars, and differential-phase measurements to detect "hot Jupiters" by their direct emission. First fringes with the interferometer were obtained in March 2001 using the two Kecks with their adaptive optics systems. Subsequent engineering work has, been focused toward the visibility mode in the areas of system validation, and improving sensitivity, increasing automation, and adding functionality in preparation for nulling and differential phase. Recently four shared-risk teams were selected by NASA to participate in early science observations, and initial shared-risk science observations have begun.