Contour plot showing the brightness temperatue of TOI-431b in the LRS bandpass as a function of the planetŠs Bond albedo and heat redistribution efficiency. The solid black line is the derived dayside temperature in the LRS bandpass, and the dotted lines show ±1 and 2σ dayside temperatures respectively. This shows that the planet is more than 1.8σ inconsistent with being a bare dark rock. Colored points show Bond albedo and heat redistribution values for solar system bodies, adopted from Q. Xue et al. (2024).