An Atlas of Spectroheliograms from 3641 to 6600 Å

Abstract: We present a spectral atlas of solar spectroheliograms covering the wavelength range from 3641 to 6600 \AA, with continuous coverage between 3711 and 5300 \AA, and sparser coverage beyond this range. The spectral resolution varies between R $\sim$ 20 000 and 40 000, with a spectral step size between 60 and 90 m\AA, while the spatial resolution averages around 2.5 arcseconds. These observations were acquired over three months during the 2025 solar maximum, using amateur spectroheliographs (Sol'Ex and ML Astro SHG 700). The atlas is accessible via an interactive online platform with navigation tools and direct access to individual spectroheliograms.