Date: November 15, 2009

Title: The Royal Family of Astronomy

Podcaster: Ted Haulley

Organization: None

Description: November 15 is the birthday of William Herschel, who may have been the finest observational astronomer of all time. He was just one in a line of Herschels who left a mark on astronomy. This podcast will take a quick look at the lives of the Herschels who pioneered the study of astronomy in so many ways.

Bio: An amateur astronomer and hopeful historian, Ted Haulley is currently waiting for acceptance into a Masters program. He keeps busy taking care of his two girls, Tanda and Trillian. A veteran of the U.S. Navy, he still is active in the reserves. His wife Tammie is still on active duty, currently stationed in Richmond, Virginia. This is his fourth podcast for the 365 Days of Astronomy and he would like to thank everyone who took the time to comment about his previous podcasts. The positive comments have made it a great experience.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by the American Association of Variable Star Observers, the world’s leader in variable star data and information, bringing professional and amateur astronomers together to observe and analyze variable stars, and promoting research and education using variable star data. Visit the AAVSO on the web at www.aavso.org

Transcript:

The Royal Family of Astronomy: The Herschels

Hello again! This is Ted Haulley, an amateur astronomer speaking to you from just outside of Washington, D.C. in Waldorf, Maryland. Galileo may have pioneered observational astronomy, but today we will celebrate the birthday of a man who many consider the finest observational astronomer of all time. William Herschel was born on November 15, 1738, and not only would he leave a legacy of his own discoveries, but he was the first in a line of Herschels that would all make contributions to the field of astronomy. Today let’s celebrate with a few quick biographies of the most prominent members of this royal family of astronomy.

William Herschel was born in Hanover, Germany, the son of Isaac Herschel, a musician in the Hanoverian Guard. When he was 14 or 15, William joined his father in the guard as an oboist. In 1757, early in the Seven Years’ War, William fled to England. He struggled for many years making a living as an organist, composer, and music teacher. He did manage to compose a few symphonies and concertos, samples of which you can hear in the background. He finally landed a steady job as an organist for a prominent chapel in the town of Bath in 1766.

Now that he finally had job security he was able to pursue his other interests, including astronomy. He began an astronomical diary and made the first recorded observations in 1766, the same year he started working in Bath. William became what we would call today a hard-core amateur astronomer. He studied optics and would eventually construct several of his own telescopes. By 1776 he constructed a 12 inch reflector with a 20 foot focal length.

For the next few years William worked to improve the optics of his telescope, built another telescope, and began a survey of the brightest stars to identify double stars, eventually recording 848 double and multiple stars. All this and he still had a day job as a composer, organist, conductor, and music teacher.

William’s greatest discovery came on March 13, 1781. He was looking for double stars in the constellation of Gemini when he came across an object that had been mistaken by others as a star. His observational skills were better, and he had better optics, so he instantly knew that it was not just a plain star. Originally he thought he discovered a comet, but eventually he realized that is was not a comet, but a planet. The first planet discovered in the solar system outside of the planets that were known since antiquity. He wanted to call it Georgium Sidus ‘George’s star,’ in honor of fellow Hanoverian and King of England, George III, but the planet would eventually become called u-RAY-nus, or U-ran-us for everyone who wants to avoid juvenile giggles.

The name George’s star didn’t stick, but the brown nosing worked. King George III gave William a pension so he could continue with astronomy full time. In addition to Uranus, William discovered two of her moons in 1787, Oberon and Titania, and later correctly argued that they have a retrograde orbit. He then discovered two more moons of Saturn, Enceladus and Mimas in 1789.

In 1788 he married a wealthy widow, Mary Baldwin, and built a 48 inch, 40 foot focal length telescope that would be the largest telescope in the world for about 60 years. His only son, John, was born in 1792. More on him later. William was knighted in 1816, and became the first president of the Royal Astronomical Society in 1821.

With all his fame for solar system discoveries, William’s primary work went into studies of stars and nebulae. He began searching for the 103 nebulae of Charles Messier’s list. Messier saw them as things for comet hunters to avoid. William saw them completely different. He studied their structures and coined the term for one type of deep sky object that we use today; globular clusters. He speculated on the nature of the different types of nebulae, but many of his conclusions turned out to be incorrect. He did prove that some double stars are not just what we would call today optical doubles, but that they are gravitationally linked. This was the first evidence that Newton’s laws of gravity applied outside of the solar system. He also analyzed the proper motions of the stars and showed that the sun itself is in motion toward the star Lambda Hercules.

William died on August 25, 1822 with a great legacy of discoveries, but the legacy of the Herschel family was just beginning.

Next up is William’s sister Caroline. William’s assistant and comet hunter was born in Hanover on March 16, 1750. She joined her brother in England in 1772 to pursue a singing career, but she soon got caught up in William’s astronomy habit. She assisted him in recording observations, grinding and polishing mirrors, preparing data for publication, and was the mistress of the house until William got married. Her assistance to William was so vital that she was awarded a government pension of her own in 1787.

She also began making observations of her own, discovering her first comet in 1786, her second in 1788, and two more in 1790. The final totals of her discoveries are eight comets and three nebulae, in addition to all her day work compiling William’s observations from the previous night.

When William died in 1822 she retired to Hanover, but she still assisted her nephew John with her final contribution to astronomy. She compiled, edited, and arranged William’s observations of nebulae and star clusters into one catalogue. This work won her the Royal Astronomical Society’s Gold Medal in 1828. She died on January 9, 1848 with an added legacy of a pioneering woman in the field of astronomy.

Next up is William’s son, John. John Herschel was born on March 7, 1792. After graduating from Cambridge in 1813 he first considered a career in law, but turned to astronomy in 1816. He continued his father’s work on double stars and nebulae. He married in 1829 and had twelve children.

He eventually became one of the most famous scientists of the day, and was knighted in 1831. He already had a legacy of his own when he decided to work on his father’s legacy of cataloging nebula. William did all his observations from England, so in 1833 John traveled to South Africa to catalog the southern skies. He spent 5 years in South Africa, cataloging thousands of nebulae and double stars. He eventually published a consolidated catalog of the entire sky of 5,000 nebulae, most of which were discovered by him or his father. The catalog was published in 1864 and is an ancestor to the New General Catalogue, or NGC, that we use today.

John died on May 11, 1871 and was so highly regarded by contemporaries that he was buried next to Isaac Newton at Westminster Abbey.

John’s legacy goes beyond astronomy. He published books on meteorology, physics, and geography. He was also a pioneer in the science of photography, and if often credited with coining the term ‘photography.’

The last Herschel for today is Alexander. The fifth of John Herschel’s twelve children was born in South Africa on February 5, 1836. He graduated Cambridge University in 1859, and received additional training at the Royal School of Mines in London. He became a professor of mechanical and experimental physics at the Andersonian University of Glasgow in 1866, and then professor of physics and experimental philosophy at the University of Durham College of Science at Newcastle.

Alexander’s primary field of research was meteors. He published over 40 papers on his observations. His most recognizable contributions to modern astronomy was to identify the radiant points of various annual meteor showers and providing evidence that meteor showers are related to comets. He was able to identify which comets were responsible for several of the annual meteor showers. He died a bachelor in June 18, 1907, the last of a dynasty of astronomers who made contributions that are still recognizable today.

As always, I welcome all comments. You can reach me at thaulley@yahoo.com, and now you can friend me on Facebook for more astronomical anniversaries and some observing suggestions for naked eye and binocular observers. Thanks for listening.

End of podcast:

365 Days of Astronomy
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