THE HERSCHELS

A Family Affair with Astronomy

All of us know about families in which the parents are smart and the kids get good grades and do great extracurricular activities. The Herschels of England were that kind of family, starting with Sir Frederick William Herschel (1738–1822), his sister Caroline (1750–1848), and his son John (1792–1871). Between them, this talented trio of German-English stargazers were responsible for:

• Discovering one planet
• Charting hundreds of double and triple star systems
• Discovering planetary nebulae
• Completing deep-sky surveys of distant non-stellar objects including nebulae, galaxies, and comets
• Discovering infrared light
• Creating massive catalogs of sky objects still in use to this day

As if that weren’t enough, the trio built telescopes and even explored the world of the very small by examining plants and animals under the microscope. Their work is enshrined in the Herschel Museum of Astronomy in Bath, England.

The Clan Patriarch

Sir Frederick William Herschel was born in Hannover, Germany, in 1738. He trained as a musician and eventually composed twenty-four symphonies. He played violin, cello, oboe, harpsichord, and the organ. He moved to England, where he was first violin for the Newcastle orchestra. From there, he moved to Leeds, where he took a job as a church organist and ended up becoming director of the Bath orchestra. His love of music eventually led him to explore mathematics and the study of optics. He made friends with the Royal Astronomer, Sir Nevil Maskelyne, and began building telescopes.

In 1773 Herschel commenced recording numerous observations of the stars and planets. He kept careful observational journals all his life, often going back and re-observing double stars and other distant objects to note any changes in their appearances or positions. His notes formed the basis of his famous Deep Sky Catalog and Double Star Catalog, as well as his Catalogue of 500 New Nebulae, Nebulous Stars, Planetary Nebulae, and Clusters of Stars. Using his observations of the stars over the years, Sir William Herschel was also able to suggest that the Milky Way Galaxy had a disk-shaped structure.

Discovering Uranus

Sir William Herschel spent much of his time searching for double stars and ultimately found nearly a thousand multiple-star systems. As he was observing in March 1781, he thought he spotted something that looked distinctly non-stellar. He marked it down as a possible star or comet and moved on. Further observations showed that it was moving, although very, very slowly. Herschel worked with a Russian scientist named Anders Lexell (1740–1784), who calculated an orbit for this mysterious object and suggested that Herschel’s discovery could be a planet. Herschel looked at the data and agreed. He named his find the “Georgian star” after King George III of England, but the convention was to name planets after classical mythological features. So, Herschel’s discovery became known as Uranus after the Greek god of the heavens.

Caroline Herschel

At a time when women were not expected to have much interest in science, Caroline Herschel was as intrigued by the night sky as her famous brother, Sir William Herschel. She was born in 1750 and grew up a sickly child. When she was seventeen, she left the family home and moved in with William, who had emigrated to England. Like her brother, she studied music and became an accomplished vocalist. Also like William, Caroline was bitten by the astronomy bug. She worked with him as he built ever better telescopes, lending her hand at mirror polishing and mounting the telescope hardware. Her brother taught her how to reduce data, and she began doing her own observations. She discovered eight comets, and eventually the government recognized her services, particularly in support of Sir William’s research, by paying her for her work. She may well be the first woman in modern time to be paid to do astronomy, and she spent much of her life re-observing and verifying her brother’s original astronomical targets.

Sir John Frederick William Herschel

Like his father and aunt, Sir John Herschel was interested in mathematics, astronomy, botany, and chemistry. He became interested in astronomy in 1816 and built his first telescope. It wasn’t long before he was following in his father’s footsteps as an observational astronomer. He re-observed many of the multiple star systems catalogued by his father and devised the Julian day calendar system. In 1833, Sir John and his wife traveled to South Africa, a trip that allowed him to complete his father’s survey of stars and nebulae. He published The General Catalog of 10,300 Multiple and Double Stars, as well as the New General Catalog of Nebulae and Clusters (which is referred to today as the NGC).