a major astronomical observatory, located at Simeis in Crimea, Ukraine. Established in the early 1900s, the observatory houses modern optical reflecting telescopes with diameters of 1.20 and 2.65 m (3.94 and 8.69 feet). It also operates several small radio telescopes, the most important of which is a high-precision, steerable paraboloid, 22 m (72 feet) in diameter.