The BlackGEM array will consist of, initially, three, wide-field 65cm telescopes, each with a 2.7 square degree field-of-view at 0.56"/pix. Installation will be at ESO La Silla in mid-2018. The prototype system MeerLICHT will be installed at SAAO Sutherland (ZA) in spring 2017. Sensitivity of BlackGEM will be g=23 at S/N=5 in five minutes in dark conditions. The telescope design has been optimized for image quality to take advantage of the excellent site. The primary objective of the BlackGEM project is to detect optical counterparts to gravitational wave events. To achieve this, the project will also perform: a) a Southern All Sky Survey (in the u,g,r,i,z and broad-band q filters) down to 23rd mag over 30 000 square degrees, b) a Fast Synoptic Survey to characterize fast variability (minutes -days) down to 23rd magnitude on a 1-minute cadence in multiple filters over hundreds of square degrees, and c) a Twilight program to monitor bright galaxies out to 30 Mpc on a daily basis. As part of the All Sky Survey a regular bi-weekly scan of the available sky (10,000 sqd) will be performed in the broad-band (420-720) q-band filter.
BlackGEM will be a 'Southern PTF' or an 'LSST-lite', taking full advantage of its Southern location and the excellent conditions at the La Silla site. BlackGEM is developed by a consortium consisting of NOVA, Radboud University and KU Leuven. The consortium is open for new partners and/or collaborations.