Sir Frederick William Herschel

1738-1822

German-English Musician and Astronomer

William Herschel is considered the founder of modern quantitative astronomy. His major accomplishments include his presentation of the first thorough and systematic study of celestial objects beyond the solar system, the discovery of the planet Uranus, and discovery of infrared radiation.

Herschel was born in Hanover, Germany. His father was an accomplished musician, oboist, and bandmaster of the Hanovarian Foot Guards. Young Herschel trained as a musician and became a member of his father's band. In 1757, during the Seven Years War, he escaped to England where he quickly established himself, first as a music copier, then as a performer and composer. In 1766 he became the organist of the chapel in Bath, a resort city in southeastern England. His sister Caroline joined him in 1772.

He was not satisfied with simply being a skilled musician. His innate inquisitiveness led him to try to understand musical theory as well. As a result, he read Harmonics by Robert Smith (1689-1768), which he found interesting enough to encourage him to also read Smith's A Compleat System of Opticks. The latter introduced Herschel to lenses and telescopes and resulted in a new hobby. He began to use telescopes to observe the planets and stars, becoming particularly interested in the celestial phenomena beyond the solar system. The telescopes that were available and affordable were not strong enough to observe objects at such distances, so he began to make his own. His skill grew until his telescopes were better than those at Greenwich Observatory, the center of astronomical observation in England.

He continued building telescopes and systematically surveying the heavens, making and recording accurate observations. Although these endeavors took a great deal of his time, as well as that of his sister Caroline Herschel (1750-1848) and brother Alexander who assisted him, he was still an amateur astronomer. His study of the heavens remained a hobby, bringing in no income.

In 1781 he observed a faint object in the sky that behaved differently from the stars. He proved that this object was a planet that had not previously been identified, the first planet discovered since prehistoric times. He named the planet after the reigning English king, George III, but it is known today as Uranus. The announcement of his discovery brought him instant fame. He was awarded the Copley Medal by the Royal Society of London, which also elected him to membership. In 1782 he was granted a salaried position as the king's astronomer.

He was then able to devote himself totally to astronomy. He discovered moons associated with Uranus and Saturn, resolved nebulae into clusters of individual stars, and proposed a theory of the evolutionary origin of the universe. He measured the brightness of stars and cataloged thousands of nebulae, star clusters, and double stars. His method of systematically surveying the sky and accurately recording the positions of stars remains a basic method in astronomy today. Of particular importance to science in general was his discovery, in 1800, of "invisible light" from the stars. He showed that this "invisible light," now known as infrared radiation, displayed many of the properties of light even though it was not a part of the visible spectrum. Infrared radiation has found extensive use in science and technology. As a result of his pioneering work, Herschel was knighted in 1816.

His sister Caroline, who assisted him in his work until his death, became a recognized astronomer herself. She discovered eight comets and three nebulae and received the gold medal from the Royal Astronomical Society in 1828.

Herschel was also assisted by his wife Mary, whom he married in 1788, and by his son John Frederick William Herschel (1792-1871) who continued his father's studies of nebulae and also became a pioneer in the development of photography.

J. WILLIAM MONCRIEF