Protostars and Protoplanetary Disks with JWST

Understanding how stars and planets form requires observations at long wavelengths in order to penetrate their dusty natal clouds. Thanks to its high sensitivity and resolution, JWST is a major step forward in studying the physical and chemical structure of protostellar systems (disk winds, outflows, hot cores, cold envelopes) and protoplanetary disks. This talk will present an overview of recent results on gaseous and icy molecules, most notably from the MIRI guaranteed time programs JOYS and MINDS. H2, H2O, CO2, C2H2 and a variety of simple and more complex organic species will be discussed. Together with related ALMA studies, the JWST data point to a rich chemistry with a diverse composition and C/O ratio in the inner planet-forming zones of disks that may be – surprisingly! – linked to stellar mass as well as to the presence of dust traps in the outer disk. Various models that are being developed to explain this diversity will be discussed. These differences may affect what kind of planets are ultimately made, water rich or carbon rich?