In this International Year of the Periodic Table, we suggest that three unsung women — Yvette Cauchois, Berta Karlik and Traude Bernert — should also be celebrated (see B. Van Tiggelen and A. Lykknes Nature 565, 559–561; 2019). They all contributed to the discovery of the halogen astatine (At), one of the rarest elements in Earth’s crust.

Astatine (atomic number 85) is radioactive. Cauchois and Horia Hulubei first detected the isotope astatine-218 in a sample of radon-222 in 1939 in Paris (M. Thoennessen Int. J. Mod. Phys. E 25, 1630004; 2016). Karlik and Bernert subsequently reported 218At (in 1942), then 216At and 215At (in 1943), in natural samples at the Institute for Radium Research in Vienna (B. Karlik Monatsh. Chemie 77, 348–351; 1947). And Dale Corson, Kenneth MacKenzie and Emilio Segrè synthesized and chemically characterized 211At, which doesn’t occur naturally, in 1940 in Berkeley, California.

Misperceptions about allegiances during the Second World War could have influenced those adjudicating discovery assignments (see B. F. Thornton and S. C. Burdette Bull. Hist. Chem. 35, 86–96; 2010), and Cauchois and Hulubei’s experiments were largely forgotten. With the acceptance of synthetic elements into the periodic table, element 85 was credited to the Berkeley group.