Target Comments IC 1318, the "Butterfly Nebula", is part of the larger mass of emission nebulae surrounding Gamma Cygni, which the Arab astronomers named "Sadr." Sadr -- just out of frame at the top (east) -- is the central or crux star in Cygnus, the swan. In Arabic, "sadr" means "chest", which makes sense given the star's position in Cygnus: Sadr lies at the intersection of the swan's wingspan, formed of Delta Cygni and Gienah, and its backbone, which runs from Deneb to Albireo. The dark dust lane LDN 889 separates the two halves of the Butterfly.

Image Comments This was my first remotely successful attempt at hydrogen alpha imaging. I finally got the STV guiding issues sorted and was able to successfully take many 2-minute integrations unbinned (previous efforts beyond 1 minute unbinned had 50%+ throwaway rates, but 88% of the 120 images I shot this time were keepers). There are some problems, however. Bright stars have little companion "babies" to their lefts -- this may be an internal reflection, I can't figure it out. There are a number of hot pixel trails that weren't taken out by the SD Mask combine. A median combine would probably get rid of them at the expense of some SNR. Perhaps tightening up the SD range in the combine would help. And there is a "dry brush" effect in the dim areas. This may be correlated read noise overwhelming the faint signal. Background ADUs were only about 1,100, which is well below optimal.