Asteroseismic study of the red giant in Ophiuchi

We test the possible evolutionary tracks of stars with various masses (1.8 M_odot, 1.9 M_odot, 2.0 M_odot, 2.1 M_odot, 2.2 M_odot) and metallicities Z (0.008, 0.010, 0.012), including both models with and without convective core overshooting. At a given mass and metallicity, the models with a larger overshoot predict a larger radius and age of the star. Based on the observed frequency of oscillations and the position of e Oph on the H-R diagram, we obtain two distinct better-fitting models: the solutions with mass M = 1.9 M_odot favor a radius in the range 10.55 ± 0.03 R_odot with an age of 1.01 ± 0.08 Gyr; the solutions with mass M = 2.0 M_odot favor a radius in the range 10.74 ± 0.03 R_odot with an age of 0.95 ± 0.11 Gyr. Furthermore, we investigate the influence of overshooting on the internal structure and the pulsation properties, and find that increasing the convective core overshoot significantly decreases non-radial mode inertia, while also increasing the mode amplitude. Therefore, the estimation of stellar mass and age might be modified by convective core penetration.