Top: luminosity evolution of AT 2019abn, derived from the blackbody fits to the photometry and integrated between 3000–23000 Å. The fading timescale expected if the light curve was powered by the radioactive decay of ⁵⁶Co is also indicated for reference. Bottom: radius evolution of AT 2019abn, as derived from the luminosity and temperature fits, assuming luminosity, . The data points, which are joined by solid lines represent E_B − V = 0.85, with the dashed lines representing E_B − V = 0.9 and 0.79.