Gaia17bpp opt-NIR LCs from 1950s to the present

Using the optical-to-IR spectral energy distribution (SED), we constrain the primary star to be a cool giant M0III star with effective temperature Teff=3850K and radius R=58R_{sun}_. Based on the SED fitting, we obtained a bimodal posterior distribution of primary stellar masses with a stronger preference for a 1.5M_{sun}_ mass star.

Within the last 66yr of photometric coverage, no other significant dimming events of this depth and duration were identified in the optical light curves. Using a Gaussian process, we fit a generalized Gaussian distribution to the optical and IR light curves and conclude that the dimming event exhibits moderate asymmetries from optical to IR. At the minimum of the dimming event, the Wide- field Infrared Survey Explorer color (W1-W2) differed by ~0.2mag relative to the primary star color outside the dimming event.