NICER observation list: Target ID 761701

Recent NICER and XMM-Newton observations of the isolated neutron star (INS) eRASSU J131716.9-402647 discovered significant pulsed emission at a period of 12.757s. Together with the soft and thermal spectrum, superimposed by two absorption features, and thermal luminosities that could be in excess of those derived from spin-down, this source is strikingly similar to the seven known X-ray dim isolated neutron stars. The inferred limits on the timing parameters prevent a detailed study of the intrinsic properties (e.g. magnetic field, age). We propose 4 observations with a total exposure of 110ks to establish a coherent timing solution and to perform phase-resolved spectroscopy. The results will constrain the nature and place the source in the context of the Galactic INS population.