How an Amateur Astronomer Became One of History’s Greatest Solar Observers

Sarah Laskow:

One night in Tokyo, in the years before World War II, Hisako Koyama looked up, out into space, and saw a shooting star. It could have been passing moment, one that others would miss or quickly forget. For Koyama, the impression left by the streaking meteoroid was an inspiration. Without formal training, she would go on to become an astronomer, who observed just one star, the Sun, with a dedication shared by only in a handful of people in the past 400 years. Her daily observations of the Sun’s dark spots, drawn by hand, are one of the most rigorous and valuable records of solar activity ever made, and put her alongside Galileo as a careful, dedicated observer of celestial spheres.

“The great ordinariness of her work, applied over more than 40 years, became extraordinary,” says Delores Knipp, a research professor of aerospace engineering at University of Colorado at Boulder, the lead author of a new Space Weather paper on Koyama’s life and work.