NICER observation list: Target ID 565201

Eccentric, massive colliding wind binaries are laboratories to study collisionless shocks in astrophysical settings. The best example of such a shock laboratory is WR 140, where wind-wind interactions generate variable emission from the X-ray to radio bands including dust formation. NICER monitoring will allow use to sensitively measure the physical changes of the hot shocked gas and fill in an important gap in the variation of column density. NICER provides the best measure of the colliding wind X-ray spectrum free of systematic uncertainties which occur when comparing data from different instruments. We propose to extend the NICER observations of WR 1140 with weekly monitoring through Cycle 4 as the X-ray emission begins to increase towards periastron passage in 2024.