Anyone who has studied astronomy knows that for thousands of years the only known planets other than Earth, were Mercury, Venus,Mars, Jupitar and Saturn. Then in 1781 William Herschel discovered Uranus becoming the first man since ancient times to add a planet to this list. It was only one of his many achievements.

Early Years

Born Friedrich Wilhelm Herschel in Hanover, Germany, in the year 1738, he was the second son of Isaac Herschel and his wife Ilse. William would always be close to youngest sister Caroline. It was a relationship that they would maintain for the rest of his life, and Caroline herself would become a good musician and a noted astronomer.

Isaac was an accomplished oboist, and like his father William also became a musician.

In 1753 he began playing in the Hanoverian Foot Guards Band and then in 1756 he came to England, finding work as a musical copyist in London. This was followed by a time as a choirmaster in Halifax and then as the organist at the Octagon Chapel in Bath. In 1780 he also became the director of the Bath Orchestra, and conducted some of his original music in the Pump Room. Between 1759 and 1770 Herschel wrote 18 symphonies for small orchestra, six symphonies for large orchestra and numerous other works.

Self-taught in science and mirror-making, Herschel would eventually be recognised as one of the brightest and most dedicated of astronomers. Once he became established in Bath he purchased equipment, and with the help of his brother Alexander, William began perfecting the craft of making astronomical mirrors and telescopes. Assisted by Caroline as he watched the night sky through his telescope, he found large numbers of faint patches of light which he began to methodically catalogue. This grew into the General Catalogue of Nebulae¹.

His dedication and hard work would pay off on the night of 13 March, 1781 when he discovered a celestial object and named it Georgium Sidus. But it is by the name later given it by Bode
that we know it today. Herschel had discovered the planet Uranus.

King's Astronomer

Following this discovery King George III granted him the post of Court Astronomer. The money that came with this post (£200 per annum) plus what he made selling telescopes of his own creation permitted him to turn his full attention to astronomy, to the grinding of his own lenses, and to making better telescopes.

In 1786 he moved to Slough and built a twenty foot long telescope. With it in 1787 he found the moons Titania and Oberon in orbit around Uranus. Then in 1789 he constructed the largest telescope of the day. It was forty feet long and had a forty-eight inch mirror. With it he discovered Enceladus and Mimas circling the planet Saturn. Yet most of his nebulae were discovered with a smaller scope.

He continued finding deep sky objects like nebulae and galaxies,
finding over 2500
of them in the next 20 years including the Galaxy NGC2903.
.

His studies beyond the solar system also gave him material which he published in 1783-1784 indicating that our sun and its solar system are moving within the galaxy in the direction of the constellation Hercules.

In 1783 Herschel also recorded some stars omitted from Flamsteed's
Catalogue² and reported his findings to the Royal Society of London . among these stars was
Herschels Garnet Star
(Mu Cephei) shown in the link here of the AAVSO³.

Discovering Infrared
Then one day in 1800 Herschel was observing the sun and noted that certain filters became hotter than others. He decided to conduct
an
experiment
to see if it was due to their colour. Setting up a mirror, a prism and some thermometers he checked several different colours with the thermometer and he found that the temperature increased from violet to red and the highest temperature of all was past the red. He concluded that for the invisible radiation to affect the thermometer, these calorific rays must be reflected, refracted and absorbed just like visible light. It was the discovery of infrared radiation. It would be many years before the importance of this discovery became evident.

Later Life

In 1788 at the age of fifty William married Mary Pitt at Upton and four years later they had a son John. John later became a famous astronomer in his own right.

In 1791 another musician visited Herschel and looked through his telescope. It was F. Joseph Haydn visiting from Austria. One can only imagine the two elderly gentlemen as they sat in an astronomical observatory discussing musical theory. Haydn must have been favorably impressed because he went home and publicized the symphonies of William Herschel.

In 1801 on a trip to Paris Herschel met with Pierre Simon LaPlace and Charles Messier. In 1802 at a meeting of the Royal Society of London Herschel read from his Catalogue of 500 new nebulae, nebulous stars, planetary nebulae, and clusters of stars; with remarks on the construction of the heavens . It was in this work that he first coined the term
binary star . Since that day newer catalogues have found more than 60,000 such systems. Today binary stars provide one of the best methods for finding the mass of celestial objects.

In 1816 William Herschel was knighted, and then in 1821 ( one year before his death) Herschel became president of the Royal Astronomical Society . In 1822 at the age of 84 Herschel died, and was buried beneath the tower in the Church of St. Laurence at Upton.

Recent Honours

A crater on the moon 40km in diameter was named for him in 1935. Since then craters on Mars and Mimas have also been given his name. An asteroid was named Herschel in 1960. In February,2001 a
church window
in Upton was unveiled.In 2007 the European Space Agency will launch a new orbiting infrared telescope named after him: The Herschel Space Telescope. Herschel would have been astounded to see the
Christmas Tree Cluster
(that he discovered) displayed by a modern infrared telescope.