Gilles Chabrier, astrophysicist known for his work on brown dwarfs, has joined the likes of Albert Einstein, Edwin Hubble and Stephen Hawking in being awarded the Royal Astronomical Society’s prestigious Gold Medal.

Emeritus CNRS Research Director, member of the Lyon Astrophysics Research Center (CRAL) at ENS de Lyon and Professor at the University of Exeter, Gilles Chabrier is rewarded for his outstanding contributions to the understanding of the physics of astrophysical plasmas, to stellar and planetary astrophysics, and to Galactic astronomy. The awards were announced at the Ordinary Meeting of the Society held on Friday, January 12, 2024.

Gilles Chabrier described winning the Royal Astronomical Society (RAS) Gold Medal as the "culmination of [his] scientific career".

Science has always been the dedication of my life. Receiving the Gold Medal of the RAS is a dream I would not have dared to dream when I decided to become a scientist.

As prime examples, Gilles Chabrier’s work has explored the nature of high-density environments in white dwarf interiors, leading to the transformational Segretain- Chabrier phase diagram. By developing the Saumon-Chabrier theory, he made it possible to understand the prevailing conditions inside low-mass stars, brown dwarfs, giant planets and the envelopes of white dwarfs and neutron stars, and established the Saumon-Chabrier-Van Horn equation of state. Within the field of Galactic astronomy, one of his most impactful work is the derivation of the Galactic stellar and substellar initial mass function (IMF), known as the Chabrier IMF. Now the reference IMF standard in Galactic astronomy, this function has led to he first accurate determination of the various contributions of stars, brown dwarfs and stellar remnants to the Galactic mass budget.

So many reasons why Gilles Chabrier has been awarded the RAS Gold Medal. A reward for a lifetime's work, which has already earned him the IOP Fred Hoyle Medal and Prize in 2019, the Ampère prize from the French Academy of Sciences in 2014, the Eddington medal from the Royal Astronomical Society in 2011, the Jean Ricard prize from the French Physical Society in 2010 and the CNRS silver medal in 2006.

Created exactly 200 years ago, in 1824, the Gold Medal of the Royal Astronomical Society is the Society's highest award. Since 1964, two medals have been awarded each year: one in astronomy and one in geophysics. Past winners include Einstein, Hubble, Hawking and Arthur Eddington (who, along with Einstein, was one of the first physicists to understand the early ideas of relativity). The award is generally given in recognition of a lifetime's work.