087092

Periodically pulsed X-ray emission from the nearby B2 star Rho Oph A have been discovered along with a variable magnetic field and strongly modulated radio emission. All these observations fit in a model of an oblique magnetic rotator comma where comma alternatively comma the magnetic poles and their radio emission point towards the Earth. In this proposal we request to use NuSTAR and XMM-Newton to monitor Rho Oph A for about two rotational periods openPartotal exposure virgul140 ksclosePar in order to clarify the link between X-rays comma radio emission and magnetism which requires us to firmly characterize its high energy openPar> 10 keVclosePar emission. The hard X-ray spectrum will provide a clear signature of non-thermal emission and a better knowledge of the auroral emission and particle acceleration in magnetic B stars.