Prof. Vincent Bourrier
I am an astronomer, specialized in the detection and characterization of extrasolar planets through velocimetry and transits. My main focus is on exoplanetary atmospheres, which I study via a combination of spectroscopic observations and numerical modeling to understand how they interact with their host star. I am also interested in orbital architectures (the shape of a planet orbit and its orientation relative to the star) and what they can tell us about the past dynamical evolution of planetary systems.
I recently combined both interests in the study Neptune-size planet orbiting close to a cool M dwarf star. With my collaborators, I showed that this warm Neptune orbits over the poles of its star and are surrounded by a gigantic cloud of gas escaping from its atmosphere. These surprising features are likely linked: the misalignment of GJ 436 b orbital plane suggests that it migrated close to its star in recent times under the influence of a yet-undetected companion, the increased heating by the star then triggering its atmospheric escape. The background image, drawn by comic book artist Denis Bajram, illustrates nicely these results (spaceships were not yet detected in the system)