The detection, characterization of, and search for biomarkers on exo-Earths in the habitable zones of their host stars is a long-standing goal in astronomy. As the closest solar-type star to the Sun, Alpha Cen A is an exceptional target for current and future direct imaging efforts. It offers a nearly 3-fold improvement in the angular scale of its habitable zone and a 7.5-fold boost in the absolute brightness of any planet compared to the next nearest solar-type star tau Ceti. Among the current generation of telescopes, JWST’s highly sensitive mid-infrared imaging capabilities uniquely allows us to complement existing radial velocity constraints and directly detect a mature gas giant exoplanet within Alpha Cen A’s habitable zone. A 46.9-hour Cycle 1 GO program using the MIRI F1550C coronagraph was executed in August 2024 and probed the 1-3 au separation space around Alpha Cen A where planets can survive the destabilizing influence of Alpha Cen B. In this talk, I will provide a comprehensive summary of the results from this program and place them in the context of our understanding of planet formation in binary systems as well as future opportunities with Roman/CGI and HWO. I will discuss the extensive preparations that were required to carry out these challenging observations, detail our approach to suppressing starlight from Alpha Cen AB in post-processing, and address the question: does our nearest Sun-like star host a planet?
Contact local & organisation : Pierre-Olivier LAGAGE
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