Sun Observed at Dual Frequencies

Dual freq. images of a flare
Nobeyama Radioheliograph is observing the Sun at dual frequencies. We can know the spectrum of the solar flare emission. This figure shows the 1995-11-10 flare. The upper (northern) radio source can be seen in common at 17 GHz, 34 GHz and soft X-ray, while the bottom (southern) source can only be seen in left-handed circular polarization image at 17 GHz. This means this source comes from the site where the magnetic field is strong. (Reference: Takano, T. et al., 1997, Proc. of CESRA Workshop, p.183)