Abstract of the proposal for the experiment EB100C

Fast Radio Bursts (FRBs) are millisecond-duration, extremely energetic, extragalactic transients of unknown origin. While it is clear that some FRBs could originate from magnetars, the wide range of FRB properties strongly suggests that this is not the complete explanation. Hundreds of FRBs have been discovered, but only a few have been precisely localised, allowing for a comprehensive study of their host and local environment. FRB20121102A is one such remarkable source. It is the first repeating FRB pinpointed to a dwarf host galaxy with milliarcsecond precision. The association of this FRB with a compact persistent radio source (PRS) and its extreme magnetic environment has resulted in several promising FRB production scenarios. Previous observations of this FRB with the EVN have led to groundbreaking results constraining the size of the PRS and its separation from the burst. In this proposal, we aim for long-term monitoring of the PRS on a timescale of a decade after the initial discovery. We will investigate the evolution of the flux density, spectrum, source size and the projected separation of the PRS associated with FRB20121102A at the sharpest angular scales constraining the progenitor models and shedding a light on the nature of the source.