Planetary-mass exosatellite detected around the substellar companion of a star - Kevin Hoy; Alice Zurlo; Pablo A Peña R; Jana Köhler; Silvano Desidera; Raffaele Gratton; Cecilia Lazzoni; Simon Petrus; Florian Rodler; Jonathan Smoker; Valentina D’Orazi; Ilaria Carleo; et al. (Nature, 2026)