Solar plage
Videos
A plage is a bright region in the Sun's chromosphere, typically found in and around active regions. Historically, they have been referred to as bright flocculi, in contrast to dark flocculi, and as ch
In this near true color photograph, taken through a narrowband hydrogen-alpha filter, plages are visible as overexposed patches.
Hydrogen-alpha
Videos
Hydrogen-alpha, typically shortened to H-alpha or Hα, is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and 656.46 nm in vacuum. It is the first spectral l
An amateur image of NGC 6888, using an H-alpha (3 nm bandwidth) filter