Annie S. D. Maunder

Annie Maunder joined the Royal Observatory at Greenwich as a "lady computer" in 1891 and, with her husband Walter Maunder, spent decades photographing and charting sunspots. Their butterfly diagram of 1904 showed how sunspots drift towards the solar equator through each cycle. Their study of old records highlighted the long gap in sunspots in the late seventeenth century now called the Maunder Minimum.