Macclesfield , UK
Scope: Televue NP127is @ 660mm f/l
CCD: Atik490EX @ 1×1 binning
Mount: 10-Micron GM2000HPS-II
Filters: Astrodon 3nM (Ha, SII, OIII)
Data: 12 x 30min Ha, 12 x 30min OIII, 10 x 30min SII (total 17hours).
CTB1 (Abell 85) in Cassiopeia was once classified as a planetary nebula, but later its true nature was discovered – that of being a faint supernova remnant. This target was very challenging due to the fact it is so faint and located in a dense star field which tends to hide the delicate nebula. It took a total of 17 hours of exposure using 3nM narrow band filters to reveal the detail shown here.