The 13th of March 1781 AD
English astronomer Frederick William Herschel discovered Uranus on March 13th 1781. It can also be said equally accurately that German musician and composer Friedrich Wilhelm Herschel discovered Georgium Sidus – George’s Planet – on the same date.
Herschel was born in Hanover on November 15th 1738, his father Isaac a musician in the Hanover Military Band. Wilhelm played in the Hanoverian Guards regiment band, and came to England with them (the Hanoverian royal family ruling both states at that period) in 1755. He stayed, learned English and forged a career as a music teacher, organist and orchestral leader, firstly in the North East ( Newcastle , Leeds , and Halifax ) then in Bath .
Interested in mathematics as well as music, Herschel became fascinated by astronomy in the mid-1770s, building his own telescopes to pursue what first a pastime then a passion.
Herschel’s discovery of Uranus, the seventh planet in our solar system, was made on the night of 13th March 1781. As a musician Herschel knew the importance of patronage, and he named the find Georgium Sidus in honour of George III. Herschel’s own star rose from that moment, with election to the Royal Society the same year, becoming The King’s Astronomer in 1782, and soon a knighthood followed too.
Herschel’s discovery was in fact a realisation that this was a planet rather than a star, as it had been seen and recorded as early as 1690.
Over his lifetime he built more than 400 telescopes, supplying brother astronomers with them as well as using them for his own work. His most famous piece was a for that time giant reflecting telescope with a focal length of 12m and an aperture of 1.25m. Herschel tried it for the first time on August 28 1789, and was rewarded with the discovery of a new moon of Saturn that very night – and he had to wait less than a month before discovering another one.
The name George’s Planet went down badly in other countries, and for a time it was better known as Herschel, but in 1850 in line with the naming of the other planets the name Uranus was adopted after the Greek deity of the heavens, a boon to schoolboy humour ever since.
Herschel also discovered two of Uranus’s moons in 1787, named later by his son as Oberon and Titania. Two more were discovered by Lassell in 1851, and a fifth by Kuiper in 1948. When the Voyager 2 spacecraft reached the planet in 1982 it found 10 further moons. Uranus has 11 rings, very faint unlike Saturn’s. The blue colour of the planet is caused by the methane in its atmosphere.
His home at 19 King Street Bath is now the Herschel Museum of Astronomy , but sadly for him his other work in music – 24 symphonies and many more compositions – is just a footnote to his work in mapping the skies.
Links: http://www.information-britain.co.uk/famousbrits.php?id=195 Frederick William Herschel - the discoverer
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