AAS 195th Meeting, January 2000
Session 123. HAD: Doggett, Copernicus and the Documentation of Astronomy
Oral (including Doggett Prize Lecture), Saturday, January 15, 2000, 10:00-11:30am, Regency V

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[123.03] The Impact of the Henry Draper Catalogue on 20th-century Astronomy

B. L. Welther (Harvard-Smithsonian Center for Astrophysics)

By 1900 there was a definite need to update the great star catalogues of the 19th century. First of all, the coordinates in them were pinned to the epoch of 1875. Then, too, the magnitudes were not on any systematic scale. Finally, they were all published before astronomers had any ideas or data for classifying large numbers of stars by their spectra.

Under the leadership of Edward Pickering and the financing of Anna Palmer Draper, the work on the Henry Draper Memorial began at Harvard College Observatory in the late 1880s. Its primary goal was to gather and classify the photographic spectra of about 100,000 stars. As a test case, Pickering had Williamina Fleming develop a simple classification scheme and apply it to the spectra of about 10,000 stars. The Draper Catalogue was published in 1890.

For the next two decades, Pickering worked to have astronomers approve the Harvard Classification scheme. After that happened in 1910 at the meeting of the International Solar Union, Annie Jump Cannon began the project of classifying 100,000 stars. She was so efficient that she completed the work in two years. Rather than limiting it to that number at that time, she continued classifying spectra for another two years for a total of 225,300 stars.

Although Cannon completed the classification in 1915, it was not until 1918 that the first of nine volumes of the Henry Draper Catalogue was published. At that time, it was greeted with enthusiasm and congratulations from eminent astronomers around the world: Jacobus Kapteyn in the Netherlands, Herbert Hall Turner in England, Harlow Shapley in California, to name a few. Today, the HD Catalogue is now online and endures as a source of coherent data for a wide variety of ongoing investigations of the Milky Way.

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