2017ApJ...838...31C

According to the rotational splitting law of g modes, the frequency spectra of EE Cam can be disentangled only with oscillation modes of l = 0, 1, and 2. Fifteen sets of rotational splits were found, and they contain five sets of l = 1 multiplets and 10 sets of l = 2 multiplets. The rotational period of EE Cam is deduced to be P_rot=1.84_–0.05^+0.07 days. When we do model fittings, we use two nonradial oscillation modes (f₁₁ and f₃₂), and the fundamental radial mode f₁. The fitting results show that χ² of the best-fitting model is much smaller than those of other theoretical models. The physical parameters of the best-fitting model are M = 2.04 M_☉, Z = 0.028, T_eff = 6433 K, logL/L_☉=1.416, R = 4.12 R_☉, logg=3.518, and χ²=0.00035. Furthermore, we find that f₁₁ and f₃₂ are mixed modes, which mainly characterize the features of the helium core. The fundamental radial mode f₁ mainly restricts the features of the stellar envelope. Finally, the acoustic radius τ₀ and the period separation Π₀ are determined to be 5.80 hr and 463.7 s, respectively, and the size of the helium core of EE Cam is estimated to be M_He = 0.181 M_☉ and R_He = 0.0796 R_☉.