In 2009 the International Astronomical Union (IAU) held its general assembly in Rio de Janeiro. Of the 2,109 participants, 667 (or 31.6 percent) were women. Indeed, in recent years, the fraction of women among astronomers has been growing continuously. But who is considered to have been the first female astronomer? Most would agree that this title belongs to Hypatia of Alexandria (c. 350-415 C.E.; Fig. 1), a remarkable philosopher, mathematician, and astronomer.
Figure 1. A photograph entitled "Hypatia," by the pioneering 19th-century photographer Julia Margaret Cameron. The model is Marie Spartali. (Image in the public domain.)