THE PECULIAR OF?P STARS HD 108 AND HD 191612: THE X-RAY VIEW

摘要

The peculiar Of?p spectral category notably contains two stars, HD 108 and HD 191612, that were found to display spectacular line profile variations in the visible domain: these stars apparently alternate between two different spectral states. To discover the origin of this intriguing behaviour, we undertook a multiwavelength campaign, with a special emphasis on X-ray observations. The analysis of the X-ray emission provides crucial information for constraining the nature of these peculiar objects and testing conflicting models. We have obtained high-quality XMM-Newton observations of these objects and we present here a preliminary analysis of these data.