Extended Data Figure 1: Estimating the surface differential rotation parameter.
From: A hot Jupiter orbiting a 2-million-year-old solar-mass T Tauri star
Variations of the reduced χ2 as a function of the surface differential rotation parameters Ωeq and dΩ, denoting respectively the rotation rate at the equator and the difference in rotation rate between the equator and the pole (and assuming a solar-like sine-square differential rotation law). The location of the minimum and the local paraboloid curvature yield the optimal parameters and their respective 1σ error bars19, equal to 2.29525 ± 0.00020 and 0.0172 ± 0.0014 radians per day. The outer colour contour traces the 99.99% confidence interval (corresponding to a χ2 increase of 18.4 for a two-parameter optimization problem).
