Cecilia Payne-Gaposchkin

Transformed astrophysics by revealing stars' composition of hydrogen and helium

Cecilia Payne-Gaposchkin (1900–1979), a British-American astronomer, revolutionized our understanding of stars through her 1925 doctoral thesis. By analyzing stellar spectra, she concluded that hydrogen and helium—not heavier elements, as previously assumed—were the primary components of stars. Initially dismissed, her findings were later validated, fundamentally altering astrophysics.

Despite facing gender barriers at Harvard College Observatory, Payne-Gaposchkin became the first woman to head a department there. Her work on variable stars and galactic structure paved the way for modern stellar classification. She also mentored future generations of female scientists, advocating for gender equality in academia.

Her book Stars and High Temperatures (1945) synthesized decades of research, while her perseverance inspired countless women in STEM. Today, she is celebrated as a trailblazer who decoded the universe’s chemical makeup, proving that groundbreaking science often challenges entrenched beliefs.