088378

NGC 7793 P13 is one of the best targets among the ultra-luminous X-ray pulsars openParULXPsclosePar to study how neutron stars can sustain accretion rates orders of magnitude above their Eddington limit. It has strong pulsations and a known optical counterpart comma which allowed us to determine the full orbital ephemeris using XMM- Newton data. In 2020 P13 entered an off-state comma from which it is currently re- emerging. This gives us the unique opportunity to study the accretion flow as the accretion geometry is changing and will allow us to infer more physical parameter of the system comma like the magnetic field. Therefore we propose to continue our successful campaign of AOs 17 19 to monitor the spectrum and pulse period of P13 and other sources in NGC 7793 throughout AO 20 with 2 40 ks observations.