The Lake County Astronomical Society

Astronomy Bio...Henry Draper

Jay Bitterman

Henry Draper was born in Virginia on March 7 1837. His father, John William Draper, was a distinguished physician and chemist. In 1854, at the age of 17 he entered the Medical School of the New York City University. He completed all of the medical courses at the age of 20, but because he had not reached the required age for graduation, he traveled in Europe for one year. When he was in Ireland he visited, and was greatly influenced by, William Parson's Observatory in Parsonstown (now Birr). He was appointed Professor of Natural Science at the University of the City of New York in 1860. He wove his interests in telescope making and photography, developed during his travels, into his professional career. When he returned from his travels in Europe, Draper began preparing his own glass mirror. In 1861 he installed it into his new observatory that was on his father's estate at Hastings on Hudson, New York. He started his astronomical research career by making preliminary studies of the spectra of the more common elements and photographing the solar spectrum.

By 1873 he had produced a spectrograph that was similar to Huggins' visual spectroscope; he clarified the spectral lines by using a slit and incorporating a reference spectra so that celestial elements could be identified more easily. In 1874 Draper was asked by the US commission to be acting Director of the photographic department to observe the transit of Venus.

The spectroscopic studies of Huggins and Lockyer in Europe stimulated Draper's work. During the last years of his life he worked toward acquiring high quality spectra of celestial objects. He studied the Moon, Mars, Jupiter, the comet 1881 111 and the Orion Nebula.

He also succeeded in obtaining photographs of stars that were extremely faint to the eye, by using exposure times of more than 140 minutes, thus demonstrating the advantages of astrophotography

He died unexpectedly, on November 20, 1882, of double pleurisy, at his home in New York. His widow established a fund to further support a spectral studies program. In 1886 a team at Harvard College Observatory began the program to establish a useful classification scheme for stars and a catalogue of spectra. The Harvard project, named the Henry Draper Catalogue, completed in 1897, resulted in a comprehensive classification of stars according to their spectra.