Coal Sack Loop -Reprocessed

The “Coalsack Loop” is a 10 degree diameter ring of visible emission nebulosity centred on the Coal Sack dark cloud, which is seen in projection against the Loop’s centre. It was discovered in 1998.

 

This image is a 6 pane mosaic- each pane consisting of an integration of 9 ten minute sub-exposures

 

Total integration therefore represents 9 hours of data

 

REPROCESSED to tone down background and emphasise the loop itself - which is still very very faint

 

 

Equipment

 

EQ6/ Samyang 135 mm/ L Extreme/ ASI 183MC/ ASIAIR

 

Software

 

ASIAIR/ AstroPixel Processor/Photoshop CS6/ Topaz AI/Starnet ++ v2/ Planning in Telescopius

 

 

Conditions

 

Panes 1-2 were shot through thin clouds which later presented considerable challenges in processing due to varying intensity

 

Seeing was poor throughout but this data was collected over three nights in the middle of a La Nina event when clear nights are hard to come by

 

 

Processing notes

 

AAP/ my computer struggled with constructing a mosaic with all the data in one hit- with LNC turned on it took over 18 hours and even then the stacking was poor

 

Stacked each pane separately as normal and then constucted a mosaic using the following settings:

 

Registration :

 

Mosaic

Scale stop : 15

Dynamic Distortion : ON

Projective Regsitration

 

Normalisation :

 

Advanced

 

Neutralise background : ON

 

Integration:

 

LNC 2 degrees , three iterations

MBB 17 %

Done