Henrietta Leavitt
Leavitt was employed to do practical work, analysing photographs of the stars. She was good at her job and became head of the photographic photometry department. This group studied photo images of stars to determine their magnitude.During her career, Leavitt discovered more than 2,400 variable stars, about half of the known total in her day. These stars change from bright to dim and back fairly regularly.
Some of the night sky plates taken by Harvard Observatory in Henrietta Leavitt's time are displayed here.
Small Magellanic Cloud