XMM-Newton spectroscopy of stars in open clusters and star forming regions

We discuss observations of open clusters and star forming regions obtained with the RGS and EPIC instruments on board XMM-Newton. These observations provide a powerful tool to investigate the temperature structure, emission measure distribution and elemental abundances of stars from the pre-main sequence phase to post-main sequence evolution. We report in particular on EPIC and RGS spectroscopy of hot and cool stars in the very young cluster around σ Orionis, of two stars in the Hyades (the main-sequence star VB 50 and the clump giant VB 71) and of two pre-main sequence stars in Taurus-Auriga (the classical T Tauri star SU Aur and the weak-lined T Tauri star HD 283572). The implications of these observations for models of magnetic activity in late-type stars, of wind emission in early-type stars, and of X-ray production in the early stages of stellar evolution are briefly discussed.