Stellar Occultations by Trans-Neptunian Objects – Felipe Ribas (UTFPR)

Stellar occultations provide a powerful tool to explore objects of the outer solar system. Occultations return kilometric accuracies on the three-dimensional shape of bodies irrespective of their geocentric distances, with the potential of detecting topographic features along the limb. From the shape, accurate values of albedo can be derived, and if the mass is known, the bulk density is pinned down, thus constraining the internal structure and equilibrium state of the object. Since 2013, occultations have led to the surprising discovery of ring systems around the Centaur object Chariklo, the dwarf planet Haumea and the large trans-Neptunian object Quaoar while revealing dense material around the Centaur Chiron. This suggests that rings are much more common features than previously thought. Meanwhile, they have raised new dynamical questions concerning the confining effect of resonances forced by irregular objects on ring particles. I will present the Sicardy et al. A&A Reviews paper we published in late 2024, with the field’s current status regarding the motivations, infrastructure development and main results.