The foreground of this image shows ESO’s Very Large Telescope (VLT) at the Paranal Observatory in Chile. The rich stellar backdrop to the picture includes the bright star Alpha Centauri, the closest stellar system to Earth. In late 2016 ESO signed an agreement with the Breakthrough Initiatives to adapt the VLT instrumentation to conduct a search for planets in the Alpha Centauri system. Such planets could be the targets for an eventual launch of miniature space probes by the Breakthrough Starshot Initiative.

The European Southern Observatory (ESO) has announced that it has entered into an agreement with Breakthrough Initiatives to adapt the VISIR instrument, Imager and infrared spectrometer that equips the Very Large Telescope (VLT) in Chile. The goal is to increase the performance of the instrument in the search for other potentially habitable planets in the  environment of theAlpha oh Centaur, the closest stellar system to the Earth.

The University of Liège is concerned by this agreement. Indeed, the ULg will develop with the University of Uppsala (Sweden) a new coronagraph which, affixed on the instrument VISIR of the VLT, will reduce the blinding light of the observed star, facilitating the detection of planets Located in the living area. More specifically, Olivier Absil, an astronomer at ULg and a researcher qualified at the FNRS, is responsible for providing a key component: a small (1 cm diameter only!) Transparent pellet made of synthetic diamond on which is engraved a micro- Network producing an optical vortex effect.

This device is not a first for the ULg. Similar coronographs developed at Liège already equip three of the largest telescopes in the world: the Keck telescope in Hawaii, the Large Binocular Telescope in Arizona and already the VLT in Chile. However, the new version developed for VISIR within the framework of this agreement with Breakthrough Initiatives will have an unparalleled level of performance.

These technological developments are carried out within the ERC Starting Grant, a € 1.5m grant from the European Research Council to Olivier Absil for his project to develop synthetic diamond optical vortices in order to improve detection Of exoplanets.
Directly photographing the exoplanets is a particularly complex task, one can compare it to the detection from Belgium of a firefly flying around the lighthouse of the port of Athens! Specific devices, called coronographs, must be used to attenuate the blinding light of a star and reveal the dim light from planets surrounding it. The Vortex project of Olivier Absil consists precisely in developing new types of coronographs based on an optical vortex (vortex) effect. In collaboration with his colleagues in Uppsala, Olivier Absil engraves micro-arrays on small synthetic diamond pellets in order to create such vortexes in the infrared domain. These mini-optical components are essential to see in the infinitely large … Layered on giant telescopes and space telescopes, they will detect and characterize potentially habitable exoplanets.

With Michaël Gillon and Olivier Absil, the University of Liège welcomes two researchers at the forefront in the search for exoplanets. Their methods and techniques are however different. By the technique used, the work of Michaël Gillon focuses mainly on ultra-cold stars, the only ones around which the technique of planetary transits has a good chance of detecting planets in the habitable zone. With the direct imaging technique by Olivier Absil’s coronography, it is rather stars similar to the sun that are targeted, especially Alpha Centaur who could be called twin of our sun.

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