CTB1 (SNR G116.9+00.1), vdB159, Fr1(oc), K12(oc), H21(oc), LBN576; Cassiopeia
KAF-16803 FLI Proline
Total Exposure Time: 14+ hours H:O:O:R:G:B 340:460:460:15:15:15 minutes unbinned RGB used for star color and vdB159
July 2011; Inkom, ID
Comments: CTB1 is a very, very faint supernova remnant in Cassiopeia. It is very difficult to image in any detail due to its very low surface brightness. It can mainly be imaged with H-alpha filters but it also has a small but definate OIII component. vdB159 is very small (1.5 arcmin) reflection nebula adjacent to magnitude 7.68 star BD +61 2573. Since it is not worth imaging by itself, I thought a better composition was to include CTB1. Please see the image below for some object identifications. Fr1, K12, and H21 are small open clusters.