A Bath church organist found the first new planet since antiquity
William Herschel earned his living playing the organ and writing symphonies in the spa town of Bath. In his spare hours he ground telescope mirrors, sometimes for 16 hours a day. On 13 March 1781, scanning for double stars from his back garden, he spotted a small disk that turned out to be Uranus.
Born in Hanover in 1738, Herschel played oboe in the same military band as his father. After Hanover's defeat at Hastenbeck, his father sent him to England in 1757, aged 19, where he anglicised his name. He was technically a deserter until George III pardoned him in 1782. Music carried him from militia bands in Durham to Newcastle, Halifax and finally the Octagon Chapel in Bath in 1766. He composed 24 symphonies, six of which were recorded in 2002.
Reading a treatise on musical harmony led him to the same author's book on optics, and from there to building reflecting telescopes with the help of his sister Caroline and brother Alexander. His first catalogues of double stars, presented in 1782 and 1784, listed hundreds of systems. Remeasuring them years later, he found shifts that parallax could not explain and concluded many pairs were orbiting each other under gravity, laying the foundation of binary star astronomy.
At first he took the disk he saw in Gemini for a comet. Anders Lexell calculated an orbit suggesting a planet beyond Saturn, and Herschel agreed. He named it the Georgian star after the king; the French preferred to call it Herschel, and eventually Uranus won out. Fame came overnight, bringing the Copley Medal, Royal Society fellowship and appointment as the King's Astronomer. From Datchet he sold more than 60 telescopes to astronomers across Europe.
His sky surveys between 1782 and 1802 turned up more than 2,400 nebulae, and his powerful instruments showed that many fuzzy objects were really clusters of stars. Using prisms and thermometers to study sunlight, he discovered infrared radiation. He also found two moons of Uranus, Titania and Oberon, and two of Saturn, and noticed Mars's polar caps change with the seasons. He became the first president of the Royal Astronomical Society in 1820 and died in 1822, leaving his son John to continue his work.
Source: William Herschel
