We present our latest effort to study the generation and evolution of magnetic fields in solar-like stars during their pre-main-sequence (PMS) phase. At the beginning of this phase, stars are fully convective and fast rotators and as a consequence generate intense magnetic field through dynamo action.
The question is to know how this inner magnetic field evolves as the stellar radiative core grows and the convective envelope becomes shallower, e.g Is there a primordial magnetic field buried deep inside todays’s Sun? if so, what is its origin?
To answer these questions, we have developed numerical simulations with ASH that represent a solar-like star at different stages of its evolution from its birth until it reaches the zero-age main sequence (ZAMS) and then evolves on the main sequence to reach the solar age. In this poster we focus on the PMS.
We have performed several simulations that have different radiative core size coupled to an outer turbulent convective envelope and different rotation rate as they contract toward the ZAMS. We have then computed how dynamo action is being modified by the different global stellar parameters and used as seed magnetic field the dynamo-generated magnetic field from the younger less evolved model. We report on how the magnetic field evolve and how the transition between radiative interior and convective envelope impact the field topology.