Herschel was a famous astronomer and telescope maker who lived from 1738 to 1822

The science and art of astronomy and telescope making owes a lot to William and his sister Caroline. He was a famous astronomer and held the title of "Kings Astronomer:" And he was the most renowned astronomer of his time. As a telescope maker his largest telescope remained the largest in the world for about 50 years. He did a lot of work and made some important discoveries in the field of astronomy. But his most famous achievements were his telescopes. He built over 400 of them and they got progressively larger until the largest one was built which was over 40 feet in length with an aperture of 49 and 1/2 inches. This telescope is pictured below at left.

A Claim To Fame and the Calling of Professional Astronomer
He was an avid amateur astronomer but this turned to a full time profession when he discovered the planet Uranus on March 13th, 1781. This brought him a lot of fame and is how he became the Kings Astronomer.

 

One of the unique things about his telescopes was that while there was a primary mirror as in the newtonian there was no secondary mirror. He would make his observations by peering down the tube directly at the mirror. You can envision this by looking at the picture. That would be Herschel standing on the platform. It would be raised and he would look down the tube at the mirror. In effect his head would block out some of the light gathering power of the telescope.

The 40 foot telescope that he was famous for (shown in picture) was a rather cumbersome instrument due to its size. So most of the discoveries and observations he made were with a smaller (20 foot) telescope.

 

Some of his discoveries:

• Uranus - 1781
• Two Moons of Saturn - ( Mimas and Enceladus)
• Two Moons of Uranus - ( Titania and Oberon)
• He coined the word "asteroid" from the Greek for
• He created an extensive catalog of nebulae called the Herschel Catalog (It has over 2500 listings)
• He discovered that most double stars were not optical doubles but actual binary stars that revolve around each other. This proved the first proof of Newton's laws of gravitation applied outside our solar system.

 

His sister Caroline

He gave his sister a telescope as a gift and it inspired her to pursue astronomy. She was his constant companion and note taker for his observations. But she also made many discoveries of her own including eight comets and the discovery of M110 which is the second companion to the andromeda galaxy.

The Herschel Museum of Astronomy - Their website

His home where he lived is now a museum dedicated to him, his work and that of his sister Caroline. It is located at 19 New King street in Bath England.