NICER observation list: Target ID 363901

We propose ToO monitoring observations (twice a day for 75 days) of a newly discovered tidal disruption event (TDE) in order to constrain its supermassive black hole's (SMBH) spin. Numerical studies suggest that the newly formed accretion disks in TDEs will be misaligned and will precess due to torques induced by the Lense-Thirring effect (frame-dragging). The disk precession period should be observable in X-rays and is a direct function of the black hole s spin. This novel technique to constrain spins of SMBHs relies on high-cadence X-ray observations. NICER s combination of fast maneuvering capability and large effective area makes it not only ideal but the only X-ray telescope that can track the X-ray spectrum precisely and disentangle the flux from the disk on a sub-day timescale.