Evidence for a recently ejected planet in the circumbinary disk of DG CrA

Multiple star systems are challenging environments for the formation of planets. Tidal interactions between a binary star and its planet-forming disk can truncate the disk and induce cavities, spirals, and warps in the disk. Furthermore, forming planets can be ejected from the system through dynamic interactions with the binary star, potentially explaining (part of) the observed populations of free-floating planets and directly imaged wide-orbit giant planets. As part of the DESTINYS large program with SPHERE at the VLT, we observed the young, nearby binary system DG CrA. We spatially resolve both stellar components and detect an extended circumbinary disk with complex substructures in near-infrared, (polarized) scattered light. Most strikingly, the observations reveal a radial, tail-like feature that starts at the inner disk region and extends outward beyond the outer edge of the circumbinary disk. We perform hydrodynamic modeling and find that this unique feature is most likely caused by the recent ejection of a planet. We have an accepted JWST-NIRCam program to detect this planet near the outer end of the tail feature. The DG CrA system has the potential to become a benchmark for the study of star-planet-disk interactions and the formation and ejection of planets around binary stars.