088206

Accretion in young comma low-mass stars causes emission from X-ray to NIR wavelengths. The UV emission component of protostellar accretion will be studied by the HST DDT legacy program ULLYSES in a once-in-a-generation investment of HST resources. However comma most of the accretion-powered emission comma including the UV regime comma is reprocessed X-ray radiation from the immediate post-shock emission. Therefore comma we propose simultaneous XMM-Newton RGS spectroscopy accompanying the ULLYSES monitoring targets openPar3 stars comma 5 epochs eachclosePar. This will allow us comma for the first time comma to directly identify physically related phenomena through their shared variability and to decipher the physics of accretion through line-resolved spectroscopy at X-ray and UV wavelengths.