Magnetic fields are believed to play a crucial role during the formation and early evolution of stars, hindering the fragmentation and the collapse of the parental cloud, and affecting the accretion mechanisms and feedback processes. However, several questions still need to be addressed to clarify the importance of magnetic fields, such as how strong they are, at what evolutionary stage and spatial scales their action becomes relevant.
Furthermore, the magnetic field parameters are still poorly constrained especially at small scales, i.e. few astronomical units from the central object, where the accretion disc and the base of the outflow are located. Thus we need to probe magnetic fields at different scales, at different evolutionary steps and possibly with different tracers.
In this poster, I will present our project and our recent results, in particular our preliminary analysis on the source G24.78+0.08. I will show that the magnetic field morphology around high-mass protostars can be successfully traced at different scales by using a multi-wavelength and multi-scale approach observing masers, dust and thermal lines.