William and Caroline searched
for double stars to facilitate study of the brightness distribution
of stars across the northern hemisphere, and they also went
comet hunting. It was comet-hunting that put the Herschels
squarely in the focus of public attention: the night of
March 13, 1781, William discovered a faint and fuzzy object
in the night sky that was clearly not point-like, as a star
would appear, even in very good telescopes. So William was
convinced he had discovered a comet, and lost no time telling
other astronomers about his discovery. When, over time,
other observers confirmed the fuzzy object, and enough measurements
of its position had been made, astronomers calculated the
path of this ‘comet’ around the sun. To everyone’s
surprise, the result of the calculations was a circle-like
path around the sun, not at all typical of comets. William
Herschel had not merely found another comet, but had in
fact discovered another planet in our solar system! Saturn
was no longer the outermost planet, since this new planet
was calculated to be twice the distance from the sun as
Saturn
This unexpected new planet caused a sensation,
capturing the attention of the king and public. William
Herschel put this sudden fame to good use, proposing to
call the new planet Georgium Sidum, in honor of the ruling
English King George III. The standard of using names of
ancient Greek gods or goddesses eventually dominated, and
the planet was named ‘Uranus’. Even though his
name didn’t last, George III was flattered. He visited
the Herschels to view the newly discovered member of the
solar system for himself, granted William and Caroline the
titles (which came with a handsome annual bursary) "The
King's Astronomer" and "Assistant to the King's
Astronomer", and relocated the Herschels to Slough,
which is near Windsor, allowing the royal family to star-gaze
themselves, if inclined to do so. The Herschels quit their
professional music career, instead dedicating the balance
of their lives to full-time astronomy.
At Slough, the Herschels began their life-long journey in
astronomy, first building a large telescope. This became
their favorite instrument, and was used in the rest of their
work. Patient and gifted instrument builders, they cast
and polished mirrors of outstanding quality. Utilizing these
skills, they made a business of building and selling telescopes.
Using their own telescope night after night, they never
stopped to improve on its design. William eventually proposed
a radical change to traditional Newtonian telescope design.
