Up and downs of a magnetic oblique rotator viewed at high resolution

In 2006, the Of?p star HD191612 became the second O-star where a magnetic field was discovered. It provided a benchmark to understand the Of?p phenomenon as a whole. Ten years later, an X-ray monitoring performed at high-resolution reveals the behaviour of the hottest magnetospheric plasma: it is located at ~ 2R [SUB]⊙[/SUB], hot but not extreme (log(T) ~ 7), producing unshifted lines, and displaying a very repetitive variability. A direct comparison with simulations yields an overall good agreement, with only a few further improvements needed.