Extended Data Fig. 1: Comparison of small exoplanets with measured infrared emission.
From: No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c
Following ref. 8, we show the normalized dayside brightness temperature for super-Earths (\({R}_{{\rm{p}}} < 2{R}_{\oplus }\)) with measured thermal emission, as a function of planet size (a) and maximum equilibrium temperature (b). The brightness temperatures are normalized relative to predictions for a bare rock with zero albedo and zero heat redistribution, Teq,max. The thermal emission of TRAPPIST-1 c has been detected in this work at 15 µm. The other planets are TRAPPIST-1 b (T1b in the plot; also at 15 µm) and planets that have been observed with Spitzer’s IRAC channel 2 at 4.5 µm. The uncertainties on the radius for the planets in the TRAPPIST-1 system are smaller than the marker symbol. Error bars show 1σ uncertainties.
