Description du projet
Des technologies spectrales révolutionnaires qui facilitent la détection de planètes habitables
L’existence potentielle de nombreuses autres planètes semblables à la Terre, avec des formes de vie similaires à la nôtre, ou capables de subvenir aux besoins de notre espèce, intrigue depuis longtemps les astronomes et les philosophes. Les énormes progrès réalisés en matière d’instrumentation et de puissance de traitement ont contribué à confirmer l’existence de quelques milliers d’exoplanètes dans notre galaxie. Une question cruciale, qui reste sans réponse, concerne l’existence de planètes rocheuses se trouvant dans la zone dite habitable, la région «juste comme il faut», autour d’une étoile qui n’est ni trop chaude ni trop froide, avec des températures de surface permettant la présence d’eau liquide. Le projet EXACT, financé par l’UE, optimise la manière dont nous pouvons utiliser les résolutions angulaires et spectrales de l’Extremely Large Telescope (ELT), actuellement en construction, qui sera capable de recueillir 20 fois plus de lumière que les plus grands télescopes optiques existants aujourd’hui, afin d’améliorer significativement notre capacité à caractériser les planètes peu brillantes, en particulier dans la zone habitable des étoiles proches.
Objectif
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.
Champ scientifique
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcontrol systems
- natural sciencesphysical sciencesastronomyplanetary sciencesplanetsgiant planets
- natural sciencesphysical sciencesastronomyplanetary sciencesplanetsexoplanetology
- natural sciencesphysical sciencesopticslaser physics
Programme(s)
Régime de financement
ERC-COG - Consolidator GrantInstitution d’accueil
38058 Grenoble
France