Vela Supernova Remnant
The narrow streak near the bottom left corner is the Pencil Nebula (NGC 2736), discovered by John Herschel in the 1830s. The NGC catalog lists it as a galaxy (visually, its appearance is indeed similar to an edge-on galaxy), but it is actually a filament of the Vela SNR with strong O-III emission.
The brightest emission region near the top edge is RCW 33, also known as Gum 17.
Separate four-frame mosaic images were taken through narrow-band (13 nm) H&alpha and O-III (doubly ionized oxygen) filters. The two-color picture was assembled using an approach inspired by Steve Cannistra's bicolor technique. Star sizes reduced by resampling the image 2×, applying a minimum filter, and downsampling it to the original resolution.
|Camera||:||Starlight Xpress SXV-H9 CCD camera|
|Lens||:|| Minolta 2.8/135 mm (Ha: f/2.8, O-III: f/3.5),
mounted with a home-made adapter
|Filter||:||Astronomik Ha and OIII filter|
|Mount||:||Vixen Super Polaris DX|
|Guiding||:||SBIG ST-4 autoguider|
|Dates||:||21 Mar. 2004 (Ha), 04 Mar. 2006 (O-III)|
|Exposure||:||Ha: 2x15 min; OIII: 3x10 min per frame|
|Site||:||Ha: Cederberg Observatory, O-III: Koornlandskloof Guest Farm|
|Processing||:|| Bias, dark frame, flat field correction, registration and digital development: IRAF;
mosaic assembly: SExtractor, Match, custom software and Swarp;