(a) Spherical triangle geometry defined by ﹩\hat{R}﹩, ﹩\hat{B}﹩, ﹩\hat{k}﹩ with the wave propagation direction ψ_wave shown in the POS. The shown case is for ﹩{\sigma }_{0}^{2}\lt 0﹩ (when ﹩{\sigma }_{0}^{2}\gt 0﹩ the red and blue arrows would coincide). (b) Atomic alignment ﹩{\sigma }_{0}^{2}﹩ as a function of n_e and T_e for θ_B = 30° at r = 1.3 R_⊙, computed with pyCELP. The weak T_e dependence supports treating temperature as a fixed parameter. (c) Concentration of Fe XIII 1074.7 nm emission from the POS in angular degrees (θ_obs − 90°). Computed from MAS thermodynamic models with pyCELP. Solid line: median e⁻¹ length over all rays at a given projected height; shaded region: interquartile range. Emission is concentrated within ±20°–30° of the POS.