Optical Photometry of WR140 as the Dust Formed During the 2016 Periastron Passage

Abstract

Abstract The colliding wind binary WR140 produces dust in its shocked gas every periastron passage. While the infrared light curve is very repeatable, there are noticeable changes every cycle in the optical time-series photometry. In the phases following periastron, there are optical dips in the light curve that were postulated to be caused by localized clumps in the dust produced in our line of sight. We report on the B- and V-band light curves that were recorded by the American Association of Variable Star Observers after the 2016 periastron event and briefly discuss comparisons to geometric models of the dust production to infer that these features are likely caused by localized dust clumps in the new dust shell.