What is the name of Richard Feynman's sister who became an astrophysicist?

Richard Feynman’s sister who became an astrophysicist was Joan Feynman.

Joan Feynman was born in 1927, nine years after Richard, and the two siblings grew up together in Far Rockaway, Queens. Richard encouraged her curiosity about astronomy, even though their mother discouraged the idea that women could succeed in science. Joan later recalled her brother as an important early teacher.

Her interest deepened after Richard showed her the aurora borealis near their home. She went on to study physics at Oberlin College and earned a doctorate at Syracuse University in 1958. Her career focused on astrophysics and space physics, particularly the solar wind, Earth’s magnetosphere, auroras, and geomagnetic storms.

Joan’s work was independent and substantial rather than merely an extension of her brother’s fame. She helped explain the physical origin of auroras, studied solar activity, and developed ways to estimate the high-energy particles that could strike spacecraft. She also worked at institutions including NASA Ames, the National Center for Atmospheric Research, and NASA’s Jet Propulsion Laboratory.