William+Herschel

William Herschel!!!

Herschel's music led him to an interest in mathematics, and thence to astronomy. This interest grew stronger after 1773, and he built some telescopes and made the acquaintance of Nevil Maskelyne. He observed the Moon, measuring the heights of lunar mountains, and also worked on a catalog of double stars. double stars??? In 1783 he gave Caroline a telescope and she began to make astronomical discoveries in her own right, particularly comets. !!!!!!Herschel's 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 40 ft (12 m) focal length and an aperture 49½ inches (126 cm) in diameter. On 28 August 1789, his first night of observation using this instrument, he discovered a new moon of Saturn. A second moon followed within the first month of observation. The 40 ft (12 m) telescope proved very cumbersome, however, and most of his observations were done with a smaller telescope of 20 ft (6.1 m) focal length. Herschel discovered that unfilled telescope apertures can be used to obtain high angular resolution, something which became the essential basis for interferometric imaging in astronomy.= 1212078589