Williamina Fleming was a Scottish astronomer born in 1857. She is best known for her work at the Harvard College Observatory, where she was hired as a "computer" to help classify stars. Fleming developed a system for categorizing stars based on their spectra, which significantly advanced the field of astronomy. Fleming discovered the first white dwarf star, known as Sirius B, and identified numerous variable stars. Her contributions to the classification of stars and her role in the early days of women in science have made her a notable figure in the history of astronomy.