Skies By Africa

Images of the Heavens By Eric Africa

DWB 111, the Propeller Nebula

DWB 111
Hubble Mono H-alpha
Cygnus the Swan, or the Northern Cross, cuts through the band of the Milky Way. As a result of this location, this constellation is host to a ton of galactic clouds of gas and dust (nebulae, as discussed elsewhere in this site). One of the more unusual nebulae in the region is listed in a less-popular list than the Messier or NGC catalog of deep-space objects. The DWB catalog was compiled by H. R. Dickel, H. Wendker and J. H. Bieritz cataloging 193 distinct objects as part of their study of H-alpha emission nebula in the Cygnus X region of the sky. The 111th object in this catalog, DWB 111, has been nicknamed the Propeller Nebula.

There may be professional papers written about this region explaining the shape of this nebula. If there are, I am not aware of what mechanisms may have shaped this. What makes this of interest to me is that in this 2 x 3 degree field of view, other similar shapes can be seen. While DWB 111 shows the most distinct propeller, or "X" shape, other similar X-shapes can be made out in this field. Not surprisingly, I have not found any specifications on this object, specifically its distance from us. More than one web site listing this objects states that "... neither the distance nor the source of excitation of [this object] are known..."

The nebulae in this region are very faint. I have not tried viewing them visually at all. Only through the wonders of sensitive CCD technology combined with the dense filtering capabilities of narrow-band filters can these objects be captured from a light-polluted location like mine at all.
Constellation: Cygnus
When Visible: July - December
Distance: Unknown
Date: July - August 2006
Location: West Chester, Ohio
Exposure Details: H-alpha: 6 x 30 Minutes Binned 1x1
Equipment Used: Takahashi FSQ-106N on a Takahashi EM200 Temma-PC mount. SBIG STL-6303 camera with 5-position filter wheel and Astrodon narrowband filters. Externally guided with an SBIG
Remote Guide Head on a Borg 45ED refractor.
Acquisition Software : MaximDL, TheSky6
Processing Software: MaximDL, Photoshop CS, IrFanView