The Next-Generation Transit Survey (NGTS) array, built by a UK, German and Swiss consortium, has achieved first light at the Paranal Observatory in Chile. The installation is designed to search for exoplanets between two and eight times the size of Earth, studying them as they pass in front of their parent star.
The array consists of 12 telescopes, each of which has an aperture of 20 centimeters. The installation is being hosted by the European Southern Observatory’s (ESO) at its Paranal Observatory in northern Chile – the site of the organization’s existing and highly prolific Very Large Telescope (VLT), as well as the VISTA telescope and the under-construction European Extremely Large Telescope.
The NGTS is designed to operate robotically, monitoring the brightness of hundreds of thousands of stars. Specifically, it’s designed to look for transiting exoplanets – those passing in front of a parent star and producing light fluctuations in the process. It performs this task with the highest level of precision of any ground-based wide-field survey instrument, measuring the brightness of stars to an accuracy of one part in a thousand.
The new installation builds on previous projects, namely the UK’s SuperWASP planetary detection program and a smaller, prototype version of the NGTS array that was hosted on La Palma in the Canary Islands from 2009 to 2010.
A key goal of the project is to identify small planets that are bright enough to allow their mass to be measured. From this, the object’s density could be calculated, providing clues as to their material composition. The increased volume of detections will also present astronomers with the opportunity to study the the atmospheric signature of exoplanets as they pass in front of stars – a type of observation that has rarely been achieved.
While the NGTS’ continuous monitoring system makes it well suited to detecting transiting exoplanets, the job of further studying discoveries will be passed on to more powerful telescopes, including the VLT.