J. Castañeda

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: In this article, the authors describe the input data, models, and processing used for the astrometric content of Gaia DR2, and the validation of these results performed within the ASTR task.

TL;DR: In this article, the authors reported the observation of a compact binary coalescence involving a 22.2 -24.3 magnitude black hole and a compact object with a mass of 2.50 -2.67 magnitude.

TL;DR: It is inferred that the primary black hole mass lies within the gap produced by (pulsational) pair-instability supernova processes, with only a 0.32% probability of being below 65 M⊙, which can be considered an intermediate mass black hole (IMBH).