Norma Bipolar Nebula revisited. H-alpha (green), OII (blue), SII (red) 5 hrs each. 3nM filters. Aspen 16M on 20" PlaneWave CDK. Despite being a shorter exposure, this attempt shows more detail than the previous STL11000M shot.
Of interest is that there is virtually no SII detectable in the faint outer bubble, which is strong in OIII.We went on to do 11 hours of SII at 2x2 binning, and it just isn't there.
Norma Bipolar NebulaNarrowband