恒星物理研究组知识库

We have computed a grid of theoretical models to fit the 12 oscillation modes of HIP 80088 observed by K2. HIP 80088 is determined to be a pre-main-sequence star, in which the CN cycle has not arrived at the equilibrium state. Mass fractions of C12 and N14 in metal composition are 0.1277(-0.0049)(+0.0064) and 0.1092(-0.0074)(+0.0057), respectively, indicating that 28% of C12 have turned into N14. Meanwhile, our fitting results show that physical parameters of HIP 80088 converge to a small range: M = 1.68-1.78 M-circle dot, Z = 0.015-0.018, v(e) = 120-136 km s(-1), log g = 4.114-4.125, R = 1.882-1.914 R-circle dot, tau(0)= 7636-7723 s, and age = 9.03-10.21 Myr. Based on our model fittings, f(3) is suggested to be one radial mode, f(2), f(4), f(8), and f(11) to be four l = 1 modes, and f(1), f(5), f(6) , f(7), f(9), f(10), and f(12) to be seven l = 2 modes. In particular, we find that (f(2), f(4), f(8)) form one complete triplet with the averaged frequency spacing of 16.045 mu Hz, and (f(5), f(7), f(9), f(10)) form four components of one quintuplet with the averaged frequency spacing of 13.388 mu Hz. The two averaged frequency spacings are not equal. Based on the best-fitting model, those l = 2 modes of HIP 80088 are found to be mixed modes, which are p-dominated modes with pronounced g-mode features, while oscillation modes with l = 1 are p modes.