NICER observation list: Target ID 667201

Eccentric, massive, dust-forming colliding wind binaries provide unique laboratories to study how shocked astrophysical plasmas react to changing thermodynamic conditions and simultaneously produce X-ray emitting gas and form dust. WR140 is a long-period, highly eccentric, visual, massive evolved binary in which wind-wind interactions generate variable emission from the X-ray to radio bands and dust near periastron. JWST has now imaged about 18 dust shells around WR 140 created over the last 143 years. We propose weekly monitoring of WR 140 with NICER through Cycle 5 as the column density reaches its minimum value and the X-ray emission increase begins to accelerate as the inverse of the stellar separation as the stars move towards periastron passage on November 22, 2024.