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Exoplanet Adaptive Characterization with the ELT

Project description

Finding habitable planets gets easier with pioneering spectral technologies

The possibility that there might be lots of other Earth-like planets out there with life forms like ours, or able to support ours, has been intriguing astronomers and philosophers alike. The tremendous advances in instrumentation and processing power have helped confirm the existence of a couple of thousand exoplanets in our galaxy; a key question that remains has to do with the existence of rocky planets in the so-called habitable zone, the 'just right' region around a star that is neither too hot nor too cold, with surface temperatures consistent with the presence of liquid water. The EU-funded EXACT project is optimising the way we can use the angular and spectral resolutions of the Extremely Large Telescope (ELT) currently under construction, which will be able to gather 20 times more light than the largest existing optical telescopes today, to significant improve our ability to characterise faint planets, in particular in the habitable zone of nearby stars.


This proposal’s objective is to mature two novel technological developments to push the limits of high-contrast imaging at high-spectral resolution with the near-future extremely large telescope (ELT). I will replicate in the laboratory the observing conditions of the ELT, and the expected spectra of a variety of planets and stars using tunable lasers. First, the high-contrast imaging system of HARMONI will be emulated to produce realistic datacubes onto which post-processing algorithms will be applied to extract as best as possible the planet signal to prepare for the real observations in 2025, which will be key to understand how planets form. I will then develop two complementary technologies. The first one is a novel type of spectrometer specifically designed to characterize an exoplanet at a high spectral resolution with a high throughput, and it will be tested on sky by being coupled to state-of-the-art direct imaging instruments (KPIC & SPHERE) both to validate this concept and to provide the highest resolution spectra of young giant planets ever obtained. A very innovative variation of this spectrometer will turn it into an integral field spectrograph with a FoV perfectly suited for the characterization of planets in the habitable zone of nearby M-dwarves. The second one is an adaptive coronagraph based on an achromatic amplitude control system, which, coupled with an adaptive optics system, will maximize the SNR of the planet by creating contrast only where it is required, in spite of ever-changing amplitude and phase aberrations due to the ELT and its instruments. These technologies will be combined together on the ELT testbench to test its ultimate capability, and lead a consistent proposition for a dedicated ELT instrument design to characterize faint planets in the HZ of nearby stars, and assess the habitability.


Net EU contribution
€ 2 588 165,50
621 avenue centrale
38058 Grenoble

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Auvergne-Rhône-Alpes Rhône-Alpes Isère
Activity type
Higher or Secondary Education Establishments
Other funding
€ 0,00

Beneficiaries (2)