M. Hauser

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: 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: The ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes as mentioned in this paper, which is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100GeV and above 100 TeV.

TL;DR: In this paper, the average flux observed during an extreme gamma-ray outburst is I(>200 GeV) = (1.72$\pm$$0.05_{\rm stat}

TL;DR: Gaia Data Release 1 (Gaia DR1) as discussed by the authors contains a large amount of data collected by the Gaia satellite during the first 14 months of its operational phase, including positions, parallaxes, and proper motions to Hipparcos-type precision or better.