24 MAGGIO 2018 ore 15:00

Detection of alpha Centauri at radio wavelengths

Titolo Completo: "Detection of alpha Centauri at radio wavelengths: chromospheric emission and search for star-planet interaction" Speaker: Prof. Dr. Corrado Trigilio, INAF - Osservatorio Astrofisico di Catania (Italy)
Detection of alpha Centauri at radio wavelengths

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.