Allegheny Observatory is the observatory of the University of Pittsburgh, located in Riverview Park, Pennsylvania, 10 miles northeast of the main university campus. For most of the 20th century and up to the present, this facility has specialized in astrometric observations and its primary research goal continues to be high-precision astrometry, particularly as applied to extrasolar planets. One of its principal researchers, George Gatewood, announced in 1996 the preliminary finding of a planetary system around the nearby star Lalande 21185 (a result that has since come into serious question).
Allegheny's main instruments are the Thaw Memorial 0.76-meter (30-inch) refractor, constructed in 1914 and used in the work leading to Gatewood's discovery, and the James E. Keeler 31-inch reflector, built in 1906 and also used for astrometric research. Among the special equipment applied to extrasolar planet detection are the Multichannel Astrometric Photometer (MAP) and the more recently developed Multichannel Astrometric Photometer and Spectrometer (MAPS).