Frédéric Vachier

TL;DR: Gaia as discussed by the authors is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach.

TL;DR: The first Gaia data release, Gaia DR1 as discussed by the authors, consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues.

TL;DR: Observations of a multichord stellar occultation revealed the presence of a ring system around (10199) Chariklo, which is a Centaur—that is, one of a class of small objects orbiting primarily between Jupiter and Neptune—with an equivalent radius of 124 9 kilometres.

TL;DR: Photometric observations of a sample of asteroid pairs reveal that the primaries of pairs with mass ratios much less than 0.2 rotate rapidly, near their critical fission frequency, which concludes that asteroid pairs are formed by the rotational fission of a parent asteroid into a proto-binary system, which subsequently disrupts under its own internal system dynamics soon after formation.

TL;DR: Observations from multiple Earth-based observatories of Haumea passing in front of a distant star (a multi-chord stellar occultation) report the presence of a ring with an opacity of 0.5, which constrains the three-dimensional orientation of Haumesa and its triaxial shape, which is inconsistent with a homogeneous body in hydrostatic equilibrium.