Frederick William Herschel (November 15, 1738 - August 25, 1822) was a German-British astronomer, technical expert, and composer. Born in Hanover, Germany, he emigrated to England at age 19. His music led him to an interest in mathematics and lenses. His interest in astronomy grew and he started building his own reflecting telescopes. During the course of his career, he constructed more than four hundred telescopes. The largest and most famous of these was a reflecting telescope with a 49 inch-diameter primary mirror and a 40-foot focal length. He became famous for his discovery of the planet Uranus, along with two of its major moons (Titania and Oberon), and also discovered two moons of Saturn. From 1782 to 1802, and most intensively from 1783 to 1790, Herschel conducted systematic surveys in search of deep sky or non stellar objects. Excluding duplicated and lost entries, he ultimately discovered over 2400 objects defined by him as nebulae. In addition, he was the first person to discover the existence of infrared radiation. He is known, as well, for the twenty-four symphonies that he composed. He died in 1822 at the age of 83.
