IC405 nebula in hydrogen alpha (Ha). Also known as the 'Flaming Star Nebula'.
In the constellation Auriga. Taken with a full spectrum modified Canon 60D.
C102/f5 achromat. Ha is a particular wavelength of light produced by unionized
hydrogen (and even non-union hydrogen....) at the far end of the red spectrum
of light that is unaffected by light pollution and less affected by atmospheric
turbulence than more visible light. This makes it a viable method of
astrophotography for folks living in highly light-polluted areas.