Title: The  archetype HD 93129A at different radio scales

Abstract:
HD 93129A is an O2If* at the Carina region, an HST binary with strong radio emission. It has been 
detected from 1 to 25 GHz; its spectrum is dominated by non-thermal radiation. The  separation 
measured optically is about 60 mas, and the components are approaching. We have carried out VLBI 
observations with the LBA in order to unveil a putative colliding wind region.  Preliminary results 
and analysis of the available data will be presented.