N₂–CO₂ grid of performed simulations. The points in red are not compatible with the observations; the green points match the data. The orange, purple, and brown lines correspond respectively to the 3σ limit of Ih et al. (2023), and limits from this work from eclipse and phase curve observations. The arrows indicate a collapse of the CO₂ present in the atmosphere. The dots correspond to stable atmosphere, stars to unstable ones. The gray area indicates the atmospheres that are unstable and will collapse.