NICER observation list: Target ID 865402

Quasi-Periodic Eruptions (QPEs) were recently discovered in the optical transient ZTF19acnskyy. They have durations of 1.5 days and recurrence times of 4.5-7 days (the longest known by a factor ≳ 2) and also show the most peculiar timing behavior yet. At peak flux >10−11 erg cm−2 s−1, it is 10x brighter than any known QPE, and its QPE amplitudes (500x quiescence) are the highest by 25x. The source shows a transient X-ray spectral feature suggestive of a relativistic outflow, which has not yet been observed in other QPEs, but will provide key diagnostic information on the radiation mechanism. In short, ZTF19acnskyy is an exemplar QPE source and only NICER can resolve its flares. Here we propose for a 245 ks monitoring campaign spanning 245 days in Cycle 7.