NICER observation list: Target ID 563501

We propose monitoring observations of of the nearest WC+O binary, Gamma2 Vel with NICER around 2 orbits during AO4. This will provide the best measure ever obtained of the change in flux, emission measures, temperatures and column densities as the X-ray emitting shock recovers from periastron passage. The derived variations in column density, temperature and X-ray flux will be compared to simulated data from detailed hydrodynamic models to constrain the shock structure in 3-D. We will also propose for ground-based monitoring of the C~III 5696 emission line and other emission lines. We will compare X-ray and available optical spectra variations to WR~140 and other WC+O binary stars to explore shock cooling and differences in dust formation from Gamma2 Vel and other WC+O binaries.