Exploiting Coherence in High-contrast Observations of ExoplanetS

Objective

"The transit method currently dominates exoplanet discovery but is limited to short-period, transiting planets, offering only partial insights into habitable zone (HZ) planets. Direct imaging, particularly through coronagraphic imaging, presents the most promising approach for characterizing HZ exoplanets and their atmospheres. Future missions like NASA's Habitable Worlds Observatory (HWO) and ELT instruments, such as the Planetary Camera & Spectrograph (PCS), aim to overcome this challenge, targeting HZ planets around Sun-like and M-dwarf stars, respectively. However, coronagraphic imaging faces significant obstacles due to the extreme star-planet flux ratios. To limit the risks faced by PCS and HWO, ESO and NASA have initiated two technology demonstrators, VLT/SPHERE+ (2027) and Roman mission (2026). They will validate innovative active wavefront correction methods, key to improve coronagraphic performance. As of today, current coronagraphs instruments have uncovered only a handful of young giant planets (YGPs). But radial velocity surveys suggest most YGPs orbit closer (5–10 au), currently right at the limit of our instruments’ capability. The upcoming Gaia release (2026) will provide hundreds of possible targets. The positioning SPHERE+, a technology demonstration with cutting edge performance, is a unique opportunity to address a dual goal: - Astrophysical: Imaging already indirectly detected YGPs using the novel ""dark-hole"" technique - Instrumental: Developing faster active wavefront correction methods and image treatment The methods developed through this ERC are unexplored and have been specifically chosen to be relevant for ground and space instruments. They will be tested on SPHERE+, serve as a foundation for the design of ELT/PCS, and could be used on Roman, with a long-term goal of direct use for HWO. Finally, a key deliverable is to provide an experimental platform for PCS&HWO technology demonstration, open to European researchers for collaboration."