2026/07/21 by Xiaoya Sun, Antonio García Hernández, Zhaoyu Zuo +5
#astro-ph.SR
We investigate the role of large separation, rotational correction order, structural resolution, and non-adiabatic effects in modelling the rotating δ Scuti star V1790 Ori. From TESS data, we extract 69 frequencies and determine Δν≃ 82 μHz. Rotating MESA models are computed at low and high resolution; their pulsation frequencies are calculated with GYRE (adiabatic/non-adiabatic, first-order rotation) and FILOU (adiabatic, second-order rotation). Using Δν as a structural constraint is necessary to reduce model degeneracy. For the selected minimum-misfit reference model, considering only the 40 modes with consistent (n,ℓ,m) labels, the RMS40 theoretical frequency differences are 0.442 μHz (resolution), 0.062 μHz (non-adiabatic), and 2.962 μHz (GYRE vs FILOU); including all 48 frequencies gives RMS48 values of 1.033, 2.326, and 3.931 μHz. Relative to observations, higher resolution reduces residuals from 4.457 to 4.387 μHz (RMS40) and from 4.715 to 4.682 μHz (RMS48); non-adiabatic effects change them marginally to 4.381 and 4.673 μHz. FILOU gives the largest residuals: 5.331 μHz (RMS40) and 5.270 μHz (RMS48). Second-order rotation produces the largest frequency shifts, but improving agreement with observations requires denser grids and self-consistent FILOU optimisation. The 260.672 μHz peak -- previously identified as the fundamental radial mode -- shows uncertain identification. The results should be interpreted as diagnostics of modelling systematics and mode-identification robustness.