NICER observation list: Target ID 261701

High mass X-ray binaries (HMXBs) consist of an early type star (companion) in orbit with a compact X-ray source. Their properties are largely determined by the interaction between the strong stellar wind from the companion and the gravity and radiation from the compact object. The compact object gravity focusses the wind and accretes. X-rays from the compact object heat and ionize the wind. In the case where the wind is strong and the X-rays are weak, then the X-ray heating effects are minimal, and the X-rays from the compact object serve as a passive probe of the structure of the wind. We propose to use Nicer to observe 4U1700-37, the HMXB with the most extreme known ratio of wind strength to X-ray luminosity.