Extended Data Table 2. Quadratic limb-darkening coefficients.

These values and errors for the quadratic coefficients u₁ and u₂ were inferred for TRAPPIST-1 from theoretical tables⁶³, and used as a priori knowledge of the stellar limb-darkening in the global MCMC analysis of the transit light curves. The error bars were obtained by propagation of the errors on the stellar gravity, metallicity, and effective temperature.

Bandpass	u 1	u 2
I (HCT/HFOSC)	0.72±0.10	0.15±0.11
I+z (TRAPPIST)	0.65±0.10	0.28±0.12
J (UKIRT/WFCAM)	0.10±0.05	0.57±0.02
NB2090 (VLT/HAWKI)	0.04±0.03	0.50±0.03