Gaia 1 and 2. A pair of new Galactic star clusters
  We present the results of the very first search for faint Milky Way
satellites in the Gaia data. Using stellar positions only, we are able to
re-discover objects detected in much deeper data as recently as the last couple
of years. While we do not identify new prominent ultra-faint dwarf galaxies, we
report the discovery of two new star clusters, Gaia 1 and Gaia 2. Gaia 1 is
particularly curious, as it is a massive (2.2$\times$10$^4$ M$_\odot$), large
($\sim$9 pc) and nearby (4.6 kpc) cluster, situated 10' away from the brightest
star on the sky, Sirius! Even though this satellite is detected at significance
in excess of 10, it was missed by previous sky surveys. We conclude that Gaia
possesses powerful and unique capabilities for satellite detection thanks to
its unrivalled angular resolution and highly efficient object classification.
