2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/186254Disks in the 6 Myr old cluster eta Chamaeleontis were searched for emission from hot H2. Around the M3 star ECHAJ0843.3-7905 we detect circumstellar gas orbiting at ~2 AU. If the gas is UV-excited, the ro-vibrational line traces a hot gas layer supported by a disk of mass ~0.03Msolar, similar to the minimum mass solar nebula. Such a gas reservoir at 6 Myr would promote the formation and inwards migration of gas giant planets.Accepted for publication in MNRAS. 9 pagesAstrophysicstext