Re_Helios

for macOS

A scanning spectroheliograph never photographs the Sun — it photographs its spectrum, one thin strip at a time, while the disk drifts across the slit. Re_Helios is a native Mac app that reads the intensity along the spectral line you choose, frame after frame, and rebuilds the whole disk as it looks at that single wavelength: hydrogen-alpha, calcium K, sodium D, helium D3, or anything else the grating can reach. Geometry correction, limb fitting, banding removal and export are all in the same pass, Metal-accelerated. Universal binary, Apple silicon and Intel, macOS 14 or later.