Hα solar images with photospheric magnetic field contours
The displayed image shows the latest Hα acquisition taken by the INAF - Catania Astrophysical Observatory, with overplotted magnetic field contours taken by HMI/SDO. When weather conditions permit, every hour a full-disc image of the Sun at the center of the Hα line (656.28 nm ± 0.25 nm) is combined with HMI measurements of the line-of-sight component of the photospheric magnetic field. Positive magnetic fields are shown in red contours, while negative magnetic fields are shown in blue. The contours correspond to +/- 200 G and +/- 1000 G. Observations in the Hα line are conducted between 8:00 and 14:00 local time (CET/CEST).