comes from the necessity to determine the upturn frequency in the so-called THz events: if the main radiation mechanism is synchrotron radiation from accelerated electrons emitting at chromospheric or coronal heights, it is expected a spectrum with a long and descending logarithmic tail towards millimeter wavelengths. In some cases this classical (textbook) shape is broken and an upturn or spectral reversion is observed. Since the reversion or upturn frequency has been estimated around 50 to 100 GHz for the observed cases, the importance of POEMAS is justified. See also Sun Chromosphere Corona Solar Flares Radio astronomy List of radio telescopes Synchrotron radiation References External links Nobeyama Radio Heliograph Official Site Nobeyama Radio Polarimeters Official Site Solar Submillimeter Telescope Official Site Astronomical instruments Radio telescopes Submillimetre telescopes Astronomical observatories in Argentina