1738-1822. German-born English astronomer. He
was a skilled telescope maker, and pioneered
the study of binary stars and nebulae. He
discovered the planet Uranus in 1781 and
infrared solar rays in 1801. Born in Hanover,
Germany, he went to England 1757 and became a
professional musician and composer while
instructing himself in mathematics and
astronomy, and constructing his own
reflecting telescopes (his 40 ft telescope
was the largest in the world at the time).
While searching for double stars, he found
Uranus, and later several of its satellites.
This brought him instant fame and, in 1782,
the post of private astronomer to George III.
He discovered the motion of double stars
around one another, and recorded it in his
Motion of the Solar System in Space 1783. In
1789 he built, at Slough, a 1.2 m/4 ft
telescope of 12 m/40 ft focal length, but he
made most use of a more satisfactory 46 cm/18
in instrument. He catalogued over 800 double
stars, and found over 2,500 nebulae,
catalogued by his sister Caroline Herschel;
this work was continued by his son John
Herschel. By studying the distribution of
stars, William established the basic form of
our Galaxy, the Milky Way.