Transmission spectrum of TOI-270 b observed with JWST/NIRSpec G395H. The spectrum is binned to R ≈ 55 for visual clarity and is shown in orange (same in all panels). The three panels show three model scenarios used to fit the observed spectrum. For the stellar heterogeneity case, we show the fit using the uninformative priors. The observed spectrum of TOI-270 b shows tentative spectral features; however, more observations are needed to confirm these. The red curves show the median retrieved model spectra, while the lighter-red contours denote the 1σ intervals. The purple points correspond to the median spectrum binned to match the observations.