Abstract

The Sun is one of the brightest radio source of the sky. However, if we
project the Sun at the distance of the nearby stars, its emission is so 
faint that no radiotelescope or interferometer would have been able so far 
to detect it at centimetric wavelenghts. Nevertheless the informations 
that is possible to derive from radio observations are of great importance 
for the study of stellar atmosfere as well as its surrounding. The new 
generation of radio interferometers has enough sensitivity to detect 
the closest solar type system, Alpha Centauri, that we observed with ATCA 
at 17 and 2.1 GHz. In this talk I'll present the results of these 
observations and what is possible to derive about atmospheric profiles and 
magnetic activity. Another important potentiality is the possibility to 
detect auroral radio emission generated to the interaction of the stellar 
magnetosphere and an orbiting planet. Even if the claimed discovery of a 
Earth planet around Alpha Cen B at the time of our observations is now  
ruled out, I take the opportunity to discuss the Auroral Radio Emission  
due to Electron Cyclotron Maser, that could be of great importance to 
detect planetary magnetic fields, whose presence is importance for the 
habitability and life protection in Earth-like exoplanets, and our 
works in progress in this field.