Wilhelm Herschel

Friedrich Wilhelm Herschel (1738–1822) was a German-born British astronomer and composer. Born in Hanover, he moved to England at age 19 and became one of the most prolific observers in the history of astronomy. Herschel was originally a musician and composer who became passionately interested in astronomy after reading Robert Smith's "A Compleat System of Opticks." He began building his own reflecting telescopes, eventually constructing over 400 of them, including the famous 40-foot telescope at Slough — the largest in the world at the time. On 13 March 1781, while systematically surveying the sky from his garden in Bath, Herschel discovered the planet Uranus — the first planet found since antiquity. This discovery brought him international fame, a fellowship of the Royal Society, and the position of King's Astronomer under George III. Herschel's observational work was extraordinary in scope. He catalogued over 2,500 nebulae and star clusters (far surpassing Messier's 110 objects), mapped the shape of the Milky Way galaxy, discovered two moons of Uranus (Titania and Oberon) and two moons of Saturn (Mimas and Enceladus), and studied the proper motion of stars to determine the Sun's movement through space. His sister Caroline Herschel was his devoted assistant and a distinguished astronomer in her own right, discovering eight comets and three nebulae. His son John Herschel continued the family tradition and extended his father's surveys to the southern hemisphere.

Discovery of the planet Uranus (1781) — the first new planet found in recorded history Discovery of infrared radiation (1800) — by measuring temperatures beyond the red end of the visible spectrum with a prism and thermometers Catalogued over 2,500 nebulae and star clusters — forming the basis for the New General Catalogue (NGC) still used today Discovered two moons of Uranus: Titania and Oberon (1787) Discovered two moons of Saturn: Mimas and Enceladus (1789) First to determine that the solar system moves through space (solar apex) Mapped the general shape of the Milky Way galaxy, correctly deducing it was a disk-shaped system Built the 40-foot telescope (1789) — the largest telescope in the world for 50 years Pioneered the study of double stars, cataloguing over 800 pairs and demonstrating that many are gravitationally bound binary systems