2019ApJ...872..156C

A grid of theoretical models are computed to fit the nine oscillation modes of IP Per detected earlier from a multi-site ground-based campaign. Fitting results show that there are two sets of theoretical models that could reproduce the observed frequencies more or less equally as well. In view of other available spectroscopic and photometric measurements, our best-fitting stellar parameters for IP Per are υ_e=91_–3⁺⁵ km s^–1, Z=0.009_–0.001^+0.004, M=1.64_–0.04^+0.10M_☉, T_eff=7766_–173⁺³⁴⁸ K, logL/L_☉=1.125_–0.046^+0.094, logg=4.041_–0.003^+0.008 dex, R=2.022_–0.018^+0.042R_☉, τ₀=8711_–35⁺⁶⁸ s, and age = 7.39_–0.46^+0.76 Myr. Meanwhile, IP Per is found to be a pre-main-sequence star where the CN cycle has not yet reached the equilibrium state. At present, 14% of C12 have been turned into N14. Based on the best-fitting model, f₆ is identified as a radial mode, f₁ and f₂ as two dipole modes, and f₃, f₄, f₅, f₇, f₈, and f₉ as six quadrupole modes.