Pickering-Fleming system

astronomy

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July 16, 2026

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The Pickering-Fleming system, developed by Edward Charles Pickering and Williamina Paton Stevens Fleming, was a pioneering method for classifying stellar spectra. Pickering, a physicist and astronomer, established the Harvard College Observatory and introduced the meridian photometer for measuring star brightness. Fleming, working at the observatory, used tens of thousands of celestial photographs to classify stellar spectra, which are patterns of lines formed by dispersing a star's light. This system allowed for the categorization of stars based on their spectral characteristics and was foundational for future astronomical work, including the discovery of numerous celestial objects and the establishment of photographic standards for measuring stellar brightness.12

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Williamina Paton Stevens Fleming
…to be known as the Pickering-Fleming system, she studied the tens of thousands of celestial photographs taken for the Draper Memorial—a project dedicated to the amateur astronomer Henry Draper of New York. In the course of her work she discovered 10 novae, 52 nebulae, and hundreds of variable stars. She…
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…to be known as the Pickering-Fleming system, she studied the tens of thousands of celestial photographs taken for the Draper Memorial—a project dedicated to the amateur astronomer Henry Draper of New York. In the course of her work she discovered 10 novae, 52 nebulae, and hundreds of variable stars. She…
Read More