« Exploring the Solar System using stellar occultations in the Gaia era » |
Bruno Sicardy |
Stellar occultations occur when a planetary bodies passes in front of a star. The spatial resolution then obtained can reach sub-km levels, something which is impossible to reach with any other techniques, including Adaptive Optics. Occultations permit, among others, to retrieve accurate shapes and sizes of remote bodies, detect very tenuous atmospheres and discover new ring systems.
The Gaia DR2 catalogs now provide sub-mas accuracy (1 mas= 1 milli-arcsec) on star positions. This hugely improved occultation predictions and allows a much more science-oriented approach, using dense meshes of observing teams in all the world, including both amateur and professional astronomers. I will highlight results that I recently obtained in the framework of the ERC project 'Lucky Star', such as the surprising discovery of rings around the Centaur object Chariklo and the dwarf planet Haumea, the monitoring of Pluto's and Triton's atmospheres, and size determinations of several large Trans-Neptunina Objects. Perspective will also be discussed, like the numerical simulation of rings around small bodies or the observation of some of the targets of the NASA/LUCY mission to the Trojan asteroids. |
vendredi 25 octobre 2019 - 11:00 Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris |
Page web du séminaire / Seminar's webpage |