Evolution of the frequencies of radial and dipole modes during the HSB phase, shown as a function of effective temperature, for a model with M = 2.4 M_⊙, X₀ = 0.7, Z = 0.008, Vrot, 0 = 45 km s⁻¹, α_MLT = 0.5, and α_ov = 0. Red lines denote radial modes (the lowest line corresponds to p₁), and the small black dots show dipole axisymmetric modes (ℓ = 1, m = 0). Horizontal lines mark the frequencies observed in the TESS light curve; the dominant frequency at 4.4416 day⁻¹ is shown in red. The shaded region marks the range of effective temperatures we derived from spectroscopy.