Western Veil (did not go well!)
Posted: Sat Aug 03, 2019 9:18 pm
An imaging session that did not go well. The session started off as an attempt to image M16, west of the meridian, which for me at the present is between Jupiter and Saturn at an elevation of around 20°. A cloud bank rolled in and M16 was on the edge. I decided to switch to the east and have a go at the Western Veil, NGC 6960. The set was to be 120x60s. With every completed frame I could see the image shift, always in the same direction. Then it dawned on me - I had set up to image west and was balanced counterweight heavy, whereas for imaging east I needed to be balanced telescope heavy. Hence the poor tracking. I don't usually bother with west as all I collect is the sky-glow from Manchester. I had to adjust the mount mid-flight which lost me about 5 frames. I got clouded out around the 80th frame. The image is best 45 of 50 - details and some observations below.
Equipment: Celestron AVX mount, Vixen 81s refractor, Altair 183C
Software: SharpCap & Siril for processing. I had to relax the roundness parameter in Siril in order to register the frames.
Frames: lights 120x60s, darks 60, flats 100, bias 100.
About 50 frames were usable and the best 45 were stacked. All processing done in Siril including crop, background extraction, colour calibration, green noise removal, histogram transformation.
Because I had not researched the object in Astronomy Tools FOV calculator http://astronomy.tools/calculators/field_of_view/, I was caught out by the size. I never realised how big the Veil Complex is https://www.skyandtelescope.com/astrono ... il-nebula/. More a target for an F/2 135mm lens or a mosaic.
Not one of my better experiences but it has served to remind me of the importance of planning/preparation and researching the object of interest beforehand.
Nil desperandum and on to the next one.
Dave
Equipment: Celestron AVX mount, Vixen 81s refractor, Altair 183C
Software: SharpCap & Siril for processing. I had to relax the roundness parameter in Siril in order to register the frames.
Frames: lights 120x60s, darks 60, flats 100, bias 100.
About 50 frames were usable and the best 45 were stacked. All processing done in Siril including crop, background extraction, colour calibration, green noise removal, histogram transformation.
Because I had not researched the object in Astronomy Tools FOV calculator http://astronomy.tools/calculators/field_of_view/, I was caught out by the size. I never realised how big the Veil Complex is https://www.skyandtelescope.com/astrono ... il-nebula/. More a target for an F/2 135mm lens or a mosaic.
Not one of my better experiences but it has served to remind me of the importance of planning/preparation and researching the object of interest beforehand.
Nil desperandum and on to the next one.
![Smile :)](./images/smilies/icon_e_smile.gif)
Dave