085260

We propose simultaneous openParNuSTAR+XMMclosePar ToO observations of a newly discovered tidal disruption flare openParTDFclosePar to constrain its supermassive black holeaquestionMarkquestionMarks openParSMBHclosePar mass and spin. Our primary goals are to openPar1closePar detect X-ray quasi-periodic oscillations openParQPOsclosePar comma and openPar2closePar study the role of the disk openParusing XMMclosePar and the corona openParwith NuSTARclosePar in exciting TDF QPOs. In the presence of an independent SMBH mass estimate comma the QPO frequency will provide a strict lower limit to the spin comma while in the absence of a mass constraint the QPO timescale will set a tight upper limit on the SMBH mass. With excellent timing capabili-ties and the ability to carry out continuous observations comma NuSTAR and XMM are ideally suited for this study whose ultimate goal is to use TDF QPOs to measure several SMBH spins.