Object(s): IC 1318, 1318A (bright nebulae), NGC 6910 (cluster)Type: Nebulae and open cluster
Distance: 5000 light years
Constellation: Cygnus
Date: 14 August and 18 September 2008
Equipment: SXV-H9, Zeiss 135mm telephoto lens
Subframes: 2 frame mosaic prepared from two lots of 30 x 300s 2x2 subframes in H alpha(unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win, mosaic in AstroArt.
At last, a spell of clear weather in this miserable year has allowed me to finish off a project I started a month ago. The area spanning nearly 4° across, centred around Sadr (gamma Cygni), consists of a complex mass of bright and dark nebulosity that can pretty much only be detected by photography (at least, from my neck of the woods).
IC 1318 forms one wing of the "Butterfly Nebula" and is the bright patch in the lower left hand corner of the above image (click on the image to enlarge -about 200K). IC 1318A is the wedge-shaped nebula in the top right hand corner. North is up and east is to the left, just how you'd see it in the sky.
The tiny cluster just above Sadr is NGC 6910, which is very much further away than the nebulae itself. Sadr is a foreground star "only" 1500 light years away, the nebulae being powered by a more distant star buried in the dark clouds of obscuring matter.
Both sessions were hampered by a bright moon, but the magic of a Hα narrow band filter eliminated any gradients or poor contrast arising from moonlight.
Needless to say, the resolution in this image can't compare with equivalents taken with big chip CCDs and wide-field Apos set on equally expensive mounts, but I'm pretty pleased with the result of my more modest set-up.
Above is a false colour image of the monochrome original, just because I can, really (click on it to enlarge if you so desire). My technique has rather clipped the fainter traces of luminosity and I think I prefer the monochrome one...
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