Sunday is the anniversary of William Huggins' birthday in 1824. Huggins was an English amateur astronomer who pioneered the science of astronomical spectroscopy. He came to astronomy later in life, as his early years were spent working in the family drapery business. Huggins' discoveries moved us toward a better understanding of the true nature of the universe. The foundation of his work was based upon findings made by men with names like Fraunhofer, Kirchoff and Bunsen.

In 1814, German optician Joseph von Fraunhofer developed the spectroscope, a tool that uses a prism to split the light of the target source and a sighting telescope observe the pattern of colors produced by the target's light. Fraunhofer originally used the device to study the dispersal pattern and properties of different kinds of glass. In addition to determining what types of glass worked best in his custom-made telescope lenses, Fraunhofer also used his spectroscope to split sunlight and found 574 dark bands vertically arrayed across the sun's spectrum.

A few decades later Gustav Kirchoff and Robert Wilhelm Bunsen, a pair of chemists based in Heidelberg, Germany, used an old cigar box and spare telescope parts to build a spectroscope. With it, they collected the spectra of samples burned in a high temperature, nonluminous flame. In 1859, they published a paper demonstrating that by pairing spectral emission and the dark bands, scientists could use a spectroscope to conduct chemical analysis and discover new elements.

Because the spectroscopic signature is unique to each element, the dark bands can be compared to fingerprints. These bands are atomic absorption lines and appear in different locations depending upon the composition of each sample. Kirchoff and Bunsen named the bands Fraunhofer lines in honor of the spectroscope's inventor.

As a young man, William Huggins became closely involved with daily operations of the family business. At the age of 30, Huggins found a buyer for the business and built a private observatory in the outskirts of London.

Huggins equipped his observatory with an 8-inch refractor telescope and a laboratory stocked with batteries and chemicals. Working at his lab bench, he produced a catalog of sample spectra which he would then compare to the spectra of different astronomical targets. He used both visual and photographic observations to collect the spectra of celestial targets.

He discovered that objects like the Cat's Eye nebula and the Orion nebula have purely gaseous emissions, meaning that they are not made of stars, whereas another object — known at the time as the Andromeda nebula — is not gaseous, and clearly shows a spectra characteristic of starlight.

Huggins' skill at astronomical spectroscopy blazed a trail that later led to the realization that the Milky Way is not the extent of the universe. And that many of the diffuse objects that appear to be nebulae are, in fact, entire other galaxies separate and far beyond the boundaries of our galactic home.

Peter Lipscomb shares the wonder of the night sky as lead guide for Astronomy Adventures and works to promote sensible and energy-efficient lighting practices. Contact him at peter@astronomyadventures.com.