Fullerenes are a class of large and remarkably stable carbonaceous molecules in the shape of a hollow sphere or ellipsoid; the best known member of the class is the archetypical "buckminsterfullerene" C60 that resembles a soccer ball (and is therefore often called "buckyball"). Dr. Cami and colleagues have recently discovered the unmistakable spectral signatures of the fullerene species C60 and C70 in Spitzer observations of a young planetary nebula, and these are now the largest molecules known to exist in space. Since this discovery, fullerenes have been reported in a wide variety of astronomical objects at abundances of typically 0.1—1.5% of the cosmic carbon. They are formed in carbon-rich evolved stars, survive in the interstellar medium and are also detected in the disks surrounding young stars. Fullerenes have many interesting properties and could play a unique role in the physics and chemistry of the interstellar medium.
In this talk, Dr. Cami will give an overview of what we have learned so far from observational analyses, with a special focus on the surprising aspects that have challenged our understanding of some of the physics and chemistry involved -- in particular about the formation and the state of fullerenes in space.