  This white paper is motivated by open questions in star formation, which can
be uniquely addressed by high resolution X-ray imaging and require an X-ray
observatory with large collecting area along good spectral resolution. A
complete census of star-forming regions in X-rays, combined with well matched
infrared (IR) data, will advance our understanding of disk survival times and
dissipation mechanisms. In addition, we will be able to directly observe the
effects of X-ray irradiation on circumstellar grain growth to compare with
grain evolution models in both high- and low-UV environments. X-rays are native
to stars at all phases of star formation and affect planet-forming disks
especially through flares. Moreover, X-rays trace magnetic fields which weave
through the flares, providing a unique, non-gravitational feedback mechanism
between disk and star. Finally, the bright X-ray emission emanating from hot
plasma associated with massive stars can have large scale impacts on the
topology of star-forming regions and their interface with the interstellar
medium (ISM).

Solar and Stellar Astrophysics;Astrophysics of Galaxies;High Energy Astrophysical Phenomena