Sylvie Vauclair

Sylvie Vauclair (born on March 7, 1946, in Saint-Germain-en-Laye) is a French astrophysicist (at the Institut de Recherche en Astrophysique et Planétologie), and professor emeritus (at the Toulouse III - Paul Sabatier University), where she taught for more than 30 years. She also taught for a decade at the Paris Diderot University. She has served as president of the Société Française d'Astronomie et d'Astrophysique. After two theses under the direction of Hubert Reeves and then Evry Schatzman, her scientific work first focused on the formation and evolution of the chemical elements that make up matter in the universe: sun, stars, primordial universe. She particularly studied the importance of the selective diffusion of atoms in stellar conditions and its consequences for their structure and evolution. She has shown the repercussions of these processes on the evolution of matter in the Universe since the Big Bang. She has made important contributions to helioseismology and asteroseismology by studying the influence of the detailed internal chemical composition on the observed frequencies. In particular, she studied the vibrations of several central stars of planetary systems to determine their precise parameters. In 2004, she participated in the discovery of the smallest known planet around the star Mu Arae. She is responsible for the discovery that the star Iota Horologii in the middle of the Hyades star cluster, observed in the Southern Hemisphere. An international symposium was held in her honor in 2013, on the topic of interactions between microscopic (atomic) and macroscopic (hydrodynamic) phenomena occurring in stars. This is a subject to which she has contributed a lot during her career, with the aim of better understanding the structure and evolution of stars. Vauclair is also a musician. She is interested in the relationship between philosophy, art and science and participates in many transdisciplinary events and in social debates.