The NOEMA radio-interferometer, located on the Plateau de Bure in the French Alps, characterized with precision the physical and chemical properties of an accretion streamer feeding a young protoplanetary disk. Although such interstellar material flows are now frequently observed, their influence on disk evolution remains poorly understood. This study shows that one of these streamers plays a major role in shaping the physical structure and chemical composition of the disk, potentially altering the conditions in which future planets form.

Led by Maxime Tanious as part of his PhD thesis supervised by Romane Le Gal and Alexandre Faure at the Institute of planetology and astrophysics of Grenoble (IPAG-OSUG – CNRS/UGA) and the Institut de radioastronomie millimétrique (IRAM – CNRS/MPG/IGN), the study is based on millimetre observations of L1489 IRS, a protostar surrounded by a disk rich in gas and dust. Thanks to the sensitivity and resolution of NOEMA, the same team that recently identified this streamer around the young system¹ was able to model its molecular emission and quantify its impact on the protoplanetary disk.


The results show that this streamer is particularly massive: it could be the source of the outer warped disk observed around L1489 IRS and could replenish several times the disk's material. From a chemical perspective, the streamer brings "fresh" material from a nearby pre-stellar core, which can alter the composition of the disk. This establishes a direct link between the chemistry of the interstellar medium and that of the regions where planets are born.

This research thus contributes to a better understanding of the chemical origin in planetary systems and to a re-examination of classical models of star formation.