Imaging low-mass planets within the habitable zone of α Centauri

K. Wagner , A. Boehle , P. Pathak , M. Kasper (1) , R. Arsenault , G. Jakob , U. Käufl , S. Leveratto , A.-L. Maire (2) , E. Pantin (3) , R. Siebenmorgen , G. Zins , O. Absil , N. Ageorges , D. Apai , A. Carlotti , É. Choquet , C. Delacroix , K. Dohlen , P. Duhoux , P. Forsberg , E. Fuenteseca , S. Gutruf , O. Guyon , E. Huby , D. Kampf , M. Karlsson , P. Kervella , J.-P. Kirchbauer , P. Klupar , J. Kolb , D. Mawet , M. N’diaye , G. Orban de Xivry , S. Quanz , A. Reutlinger , G. Ruane , M. Riquelme , C. Soenke , M. Sterzik , A. Vigan , T. de Zeeuw

1 ESO - European Southern Observatory
2 OAPD - INAF - Osservatorio Astronomico di Padova
3 AIM (UMR_7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation

Abstract Giant exoplanets on wide orbits have been directly imaged around young stars. If the thermal background in the mid-infrared can be mitigated, then exoplanets with lower masses can also be imaged. Here we present a ground-based mid-infrared observing approach that enables imaging low-mass temperate exoplanets around nearby stars, and in particular within the closest stellar system, α Centauri. Based on 75–80% of the best quality images from 100 h of cumulative observations, we demonstrate sensitivity to warm sub-Neptune-sized planets throughout much of the habitable zone of α Centauri A. This is an order of magnitude more sensitive than state-of-the-art exoplanet imaging mass detection limits. We also discuss a possible exoplanet or exozodiacal disk detection around α Centauri A. However, an instrumental artifact of unknown origin cannot be ruled out. These results demonstrate the feasibility of imaging rocky habitable-zone exoplanets with current and upcoming telescopes.

Domaines: Astrophysique [astro-ph]

K. Wagner, A. Boehle, P. Pathak, M. Kasper, R. Arsenault, et al.. Imaging low-mass planets within the habitable zone of α Centauri. Nature Communications, 2021, 12 (1), ⟨10.1038/s41467-021-21176-6⟩. ⟨insu-03373011⟩