Example of spectral fitting of the UV power-law index, β_UV, where F_λ ∝ λ^β_UV, of the stellar continuum. The grey curve shows the full NIRSpec Prism spectrum of a galaxy at z = 9.4383, with the error spectrum shown by the dotted line. The black part of the spectrum highlights the rest-frame fitting region from λ_rest = 1250 − 2600 Å. The top green bar marks the integration region for the M_UV measurements, λ = 1400 − 1700 Å in the rest frame.