Caroline Herschel – 18th Century Astronomer

Caroline Herschel c. 1829 (source)
Caroline Herschel c. 1829 (source)

As a girl, Caroline Herschel’s expectations were limited, but she had a quick mind and the ability to learn. Although most of what Caroline learned would be to benefit and help her brother, she went on to become a brilliant astronomer in her own right, discovering nebulae, star clusters, and eight comets.

Caroline Herschel was born March 16, 1750 in Hanover (now in Germany.) She was the fifth of six children born to Isaac Herschel and Anna Moritzen. Her parents were industrious and hard-working, her mother a housewife and her father a gardener and musician. Her mother saw no need to educate a girl, but Caroline was able to learn the basics of reading and writing, and because of the family talent for music, her father insisted that she learn to play the violin.

Caroline suffered a couple of childhood illnesses that left their mark; smallpox when she was three left her with scars and a damaged left eye; typhus at the age of ten stunted her growth, leaving her with an adult height of 4′ 3″. Her mother showed her little affection and envisioned Caroline as her housekeeper. Her father reminded her frequently that she was unlikely to find a husband because she had no fortune or beauty. She was probably looking at a bleak future.

In 1767, Caroline’s father died and her favorite brother William, who had moved to England, suggested that she come live with him. William’s intention was to make his living as a musician and to study astronomy, and he wanted Caroline to come keep his house. At first her mother refused to give up the work that Caroline did for her, but she agreed when William promised to send her the money to get a maid to make up for Caroline’s absence. So in 1772 at the age of 22, Caroline returned with her brother to England.

Telescope made for Caroline by William in 1795 (Photo: Wikipedia user Geni, source)
Telescope made for Caroline by William in 1795 (Photo: Wikipedia user Geni, source)

Even though she still kept house, Caroline’s life was completely different with her brother. She studied math for the first time, so that she could keep his household accounts. William gave her voice lessons and she learned to play the harpsichord so that she could accompany him. Soon she became well-known for her singing and began to get engagements for solos, although she refused if William couldn’t be the conductor. William also insisted that she take lessons in dancing and how to conduct herself in society. She thought many of the people she met in society shallow, but the lessons would serve her well because she and William soon came to the attention of King George III for their work in astronomy.

William’s astronomy work began to take up more and more of his time. Displeased with the telescopes available he began to build his own and was soon selling them to others. Caroline and their brother Alexander ground by hand the mirrors needed for the telescopes, and Caroline did William’s calculations, carefully cataloging his observations in the night sky.

On March 13, 1781, William spotted what he thought was a new comet, but after careful observation realized that it was a planet. His discovery of the planet Uranus brought him to the attention of the King. The next year William was made the official astronomer of King George III and received a pension of £200. Caroline was no longer just a helper, but an apprentice and would soon be credited with her own discoveries. This also brought with it more visibility in society and with the royal family. William and Caroline were often invited to Windsor, and Caroline got to know the princesses Sophia and Amelia as she patiently answered their questions about the stars.

Caroline never wanted to outshine her brother, but in 1783 while he was away she discovered 3 nebulae. Then on August 1, 1786, she discovered her first comet. This discovery brought her to the attention of the scientific community and The King gave her a small salary for her work as William’s assistant. It was only £50, but she wrote in her diary that it was the first money she had ever received that she felt she could spend on whatever she wished.

Sir William Herschel c. 1805 by James Sharples (source)
Sir William Herschel c. 1805 by James Sharples (source)

Around this time William got married and Caroline began doing more work on her own. Between 1788 and 1797, she discovered seven more comets and began work on revising Flamsteed’s star catalog. She verified the information, made corrections, and added 560 stars that she and William had observed. She submitted this catalog to The Royal Society for publication. But her most impressive and recognized work was The Reduction and Arrangement in the Form of Catalogue, in Zones, of All the Star-Clusters and Nebula Observed by Sir William Herschel in His Sweeps. For this work, the Royal Astronomical Society awarded her a Gold Medal calling it “a work of immense labor” and “an extraordinary monument to the unextinguished ardor of a lady of seventy-five in the cause of abstract science.”

The medal from the Royal Astronomical Society was awarded to her in 1828, six years after William’s death and after she had returned to Hanover. She also received medals from the King of Denmark and the King of Prussia, and in 1835, the Royal Astronomical Society bestowed honorary membership on two women for the first time, Caroline Herschel and Mary Somerville. The extract for the award stated that “the time is gone by when either feeling or prejudice, by whichever name it may be proper to call it, should be allowed to interfere with the payment of a well-earned tribute of respect.”

For Caroline, however, her crowning achievement probably came only a few months before she died. The work mentioned above was the basis for her nephew’s study of his fathers work. William’s vast undertaking, The Survey of the Heavens, was completed when his son Sir John Herschel completed and published the survey of the heavens in the southern hemisphere. She received a copy of Cape Observations just months before she died on January 9, 1848 at the age of 97.

Even in her death she was concerned for her brother’s fame. Her epitaph, which she composed, states in part “The eyes of her who is glorified were here below turned to the starry heavens. Her own discoveries of comets and her participation in the Immortal labors of her brother, William Herschel, bear witness of this to future ages.” Working with her brother, she advanced the science of astronomy and the recognition of women in science.

Caroline Herschel at 92 (source)
Caroline Herschel at 92 (source)

Resources
Women in Mathematics by Lynn Osen
Women in Science: Antiquity through the Nineteenth Century
by Marilyn Bailey Ogilivie
Women in Science by H. J. Mozans

Read about other Famous Women in Math and Science