NICER observation list: Target ID 668501

HESS J0632+057 is one of the rare Be binary systems detected in the TeV band. Its high-energy, non-thermal emission is mostly powered by pulsar and stellar wind collisions. Recent intra-binary shock (IBS) models were able to reproduce the global lightcurve and SED data in the X-ray and TeV bands, except a sharp peak feature which is likely caused by the pulsar intersecting the circumstellar disk. The proposed NICER observations will target the two disk passage phases suggested by the latest IBS models. With Swift and NuSTAR observation data, we aim to detect the expected hydrogen column enhancement, spectral change and short-term variability during the disk passages. These X-ray observations provide a rare opportunity of probing relativistic hydrodynamics on the pulsar-disk interactions.