While the AO is locked on a star, light from a nearby offset star
may be sent to the interferometer. The maximum offset is about 15
arcsec, but depends on position angle: please contact NExScI for
details. The minimum offset is about 0.2 arcsec. A single component of
a pair that is closer than that may be selected for interferometer
measurements by adjusting the angle tracker (KAT) settings: please
refer to the KAT section. Offset guiding may result in decreased
efficiency. Offset guiding is NOT available for the NULLING mode.
The image rotators are used in vertical angle mode.
The NASA Exoplanet Science Institute is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program.