With summer upon us the central core of the Milky Way galaxy dominates the late evening sky. This allows an astrophotographer a rich selection of targets well placed for shooting all night long.
Among these targets are the large emission nebulae… M17, M16, NGC4628, NGC6334, NGC6357, SH 2-54, and a long list of others. The brightest among these nebulae is M8, the Lagoon nebula, a rich and complex region of star formation, sweeps of gas, and dark globules.
With a new hydrogen-alpha filter added to the camera’s filter wheel it is time to re-image some of these old favorites. The filter is a narrow-band filter allowing through a slice of the spectrum only a few nano-meters wide. The filter pass-band is centered on 656nm deep in the red, the glow of neutral hydrogen gas, this allows sharp images of these glowing nebulae complexes.