The image shows the latest Hα image of the Sun acquired at INAF - Catania Astrophysical Observatory with a quality index equal to 1 (1 =good, 3 = bad). The spacing of meridians and parallels is 10 degrees.
When the weather conditions permit, every minute (between 8:00 and 14:00 local time -CET/CEST) a full disc image of the Sun in the center of the Hα line (656.28 nm ± 0.25 nm) is displayed.
The raw images are recorded with a size of 2048 x 2048 pixels and a dynamic range of 16 bit.Then, the image has been preliminarily reduced in order to check its quality and to centre the solar disc. Flat-field correction has been applied.
As of February 1, 2024, the flat-field correction is applied by default to both JPEG and FITS images. For images captured before this date, correction of FITS images requires the corresponding flat-field images.