Planet radius as a function of orbital period for known exoplanets. Confirmed planets with a 3σ or higher precision mass detection are highlighted in blue. The planets that have a mass detection smaller than 3σ precision are shown in gray. TOI-2431 b is shown in red. TOI-2431 b is the shortest period planet with both a characterized mass and radius (better than 3σ). a) TOI-2431 b compared to other USPs. b) Same as panel a, but comparing TOI-2431 b to the broader exoplanet population showing that TOI-2431 b is at the lower edge of the hot Neptune desert.