| Project Detail |
Hydrogen fusion in the radiative core of Sun-like stars drives the energy that powers these celestial bodies. However, the transition region known as the tachocline, where the radiative core meets the convective envelope, remains poorly understood. This region is crucial for generating global magnetic fields and influencing the 11-year solar cycle, but its complex interactions – such as rotation, magnetic fields, and element diffusion – are difficult to model. With the support of the Marie Sklodowska-Curie Actions programme, the DCStars project seeks to unravel these complexities through advanced global convection simulations using the DISPATCH code, focusing on the tachocline’s role in stellar dynamics and the puzzling lithium abundance in the Sun. Stars like our Sun are complex systems in which hydrogen fusion occurs in the radiative core, and heat is transported by convection in the outer part. The two most important regions in Sun-like stars are the optical surface and the transition region between the radiative core and the convective envelop, called the tachocline. The tachocline, which is believed to be responsible for generating stellar global magnetic fields (also related to the 11-year solar cycle), is a complicated region where the effect of rotation, magnetic field, diffusion of elements, and convective overshoot interplays. In this project, we will carry out global convection simulations that range from radiative interior to the lower atmosphere for the Sun and a few F-type stars using the state-of-the-art DISPATCH code. Our ab initio simulations will include complex physical processes such as rotation and magnetic fields and are free from approximations typically adopted in previous works. Based on these simulations, the applicant will quantitively study the problem of overshooting and gravity wave excitation near the tachocline, which are crucial for a better understanding of the solar modeling problem, the anomalous abundance of lithium in the Sun, and the cosmological lithium problem. |
