The Next Generation Transit Survey (NGTS)
We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars. NGTS builds on the legacy of previous surveys, most notably WASP, and is designed to achieve higher photometric precision and hence find smaller planets than have previously been detected from the ground. It also operates in red light,maximizing sensitivity to late K and earlyMdwarf stars. The survey specifications call for photometric precision of 0.1 per cent in red light over an instantaneous field of view of 100 deg2, enabling the detection of Neptune-sized exoplanets around Sun-like stars and super-Earths around M dwarfs. The survey is carried out with a purpose-built facility at Cerro Paranal, Chile, which is the premier site of the European Southern Observatory (ESO). An array of twelve 20 cm f/2.8 telescopes fitted with back-illuminated deep-depletion CCD cameras is used to survey fields intensively at intermediateGalactic latitudes. The instrument is also ideally suited to ground-based photometric follow-up of exoplanet candidates from space telescopes such as TESS, Gaia and PLATO. We present observations that combine precise autoguiding and the superb observing conditions at Paranal to provide routine photometric precision of 0.1 per cent in 1 h for stars with I-band magnitudes brighter than 13. We describe the instrument and data analysis methods as well as the status of the survey, which achieved first light in 2015 and began full-survey operations in 2016. NGTS data will be made publicly available through the ESO archive. ; The capital costs of the NGTS facility were funded by the University of Warwick, the University of Leicester, Queen's University Belfast, the University of Geneva, the Deutsches Zentrum fur Luft- und ¨ Raumfahrt e.V. (DLR; under the 'Großinvestition GI-NGTS'), the University of Cambridge and the UK Science and Technology Facilities Council (STFC; project reference ST/M001962/1). The facility is operated by the consortium institutes with support from STFC (also project ST/M001962/1). We are grateful to ESO for providing access to the Paranal site as well as generous in-kind support. The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement n. 320964 (WDTracer). The contributions at the University of Warwick by PJW, RGW, DLP, FF, DA, BTG and TL have been supported by STFC through consolidated grants ST/L000733/1 and ST/P000495/1. TL was also supported by STFC studentship 1226157. EF is funded by the Qatar National Research Foundation (programme QNRF-NPRP-X-019-1). MNG is supported by STFC studentship 1490409 as well as the Isaac Newton Studentship. JSJ acknowledges support by FONDECYT grant 1161218 and partial support by CATA-Basal (PB06, CONICYT). AJ acknowledges support from FONDECYT project 1171208, BASAL CATA PFB-06, and by the Ministry for the Economy, Development, and Tourism's Programa Iniciativa Cient´ıfica Milenio through grant IC 120009, awarded to the Millennium Institute of Astrophysics (MAS). FF acknowledges support from 'Accordo ASIINAF for PLATO' No. 2015-019-R.0 July 29, 2015.
