Specific intensity distribution for a [1500 K, 4.5] PHOENIX-DRIFT quasi-spherical symmetric model. Continuous line represents the model intensities (left label), while the dashed line denotes the deviations [model-fit] by adopting Eq. (5) and the dashed-dotted one represents the deviations by adopting Eq. (1) (right label): log[A/H] = 0.0, V_ξ = 2 km s^-1; TESS photometric system; LSM calculations.