The continuing search for the Soap Bubble nebula continued with testing the new occultation board that protects the scope from a very close streetlight and the improved cable management for the scope and attached equipment.
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The occultation board
The very stable board can be removed when not required and when the weather becomes windy
Imaging, showing the cable management and the occultation board casting shadow on the equipment
The scope is a William Optics 81mm APO refractor fitted with a ZWO EAF focuser, an o.8 reducer/flattener, an Altair magnetic filter holder v2 containing a H-alpha filter, a manual camera rotator and an SV505MC cooled monochrome, 14 bit CMOS camera. The equipment was mounted on a Celestron AVX mount.
AstroDMx Capture running on the imaging computer indoors sent the scope/mount, via an INDI server running on the same computer to the star Altair and AstroDMx Capture controlled the ZWO EAF and focused the star using a Bahtinov mask.
Focusing with a Bahtinov mask
AstroDMx Capture was used to send the mount to the star HD 228550 with repeated plate solves until an accuracy of 5 arc seconds. This star is immediately adjacent to the Soap Bubble nebula, so when the star is centred in the field of view, the nebula is virtually at the centre.
PHD2 was used for multi-star pulse auto-guiding and was controlled by a separate Linux computer indoors. An SVBONY SV165 guide scope with a QHY-5II-M guide camera was used for guiding.
Screenshot of the PHD2 auto-guiding computer
AstroDMx Capture was used to capture 70 minutes worth of 5 minute exposures east of the meridian, perform a meridian flip with plate solving and capture a further 60 minutes worth of 5 minute exposures west of the meridian.
The imaging computer indoors
Screenshot of AstroDMx Capture acquiring data
With a negative preview, which can help with visualising faint objects
Matching dark frames, Flatfields, Dark flats and bias frames were captured at the end of the imaging session.
The data were calibrated and stacked in Deep Sky Stacker, processed with the Gimp Starnet++ plugin, Neat Image, Image Magick and the Gimp 2.10.
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The Soap Bubble nebula in H-alpha light
Cropped Soap Bubble nebula
The Soap Bubble Nebula can be seen at the centre of the image.
More data, including OIII data will be collected in future imaging sessions and these data will be included in a subsequent image.
