Ground-based infrared interferometry Original Research Article

Interferometry, the coherent combination of light from apertures spaced by many meters, enables observations with angular resolution of a few milliarcseconds, and astrometric measurements with a precision in the microarcsecond range. Advances in detector technology have opened the near-infrared (IR) and thermal-IR wavelength range for interferometric observations. Scientific results from existing instruments include measurements of stellar diameters, circumstellar material in young stars, dust around evolved stars, and Mira and Cepheid pulsations. The new large facilities will soon add new techniques to our repertoire: differential astrometry, phase-referenced imaging, and nulling.