High Resolution X-ray Spectroscopy of Early-Type Stars

Although X-ray emission from massive, early-type stars has been known for almost thirty years, it is only with the advent of the high-resolution spectrographs aboard Chandra and XMM-Newton that a detailed investigation of the X-ray spectra of these stars has become possible. The existing observations of both single and binary early-type stars have been used to study the properties of their stellar winds. While some results agree with the expectations from theoretical models, other spectra show unexpected features. In this contribution, we review our current knowledge on the X-ray emission of stars of spectral type O and Wolf-Rayet and discuss the possibilities to test some new ideas with future high-resolution X-ray observations.