StarTools

Recently captured NGC 6559 the Chinese Dragon nebula over 6 x half nights. The object is on its final traverse from north to west so I only had approximately 3 hrs from sunset to gather data as my neighbours two storey house obstruct the western sky up to 30 deg.
Conditions varied greatly each night from poor to average seeing and some annoying high cloud for 2 nights
The last time I imaged this object was in 2021 with my 2600MC.
60% of the data was captured under a waning moon and remaining 40% under no moon, all under B8 City / Suburban skies.
8”f5 Klaus Helmerich Carbon fibre Newtonian Reflector
Skywatcher EQ6-R pro mount
ZWO 2600MM cooled to -10C , Gain 100 ,
ZWO 7x2” EFW
ZWO EAF
Orion 60mm guide scope with helical focuser
ZWO 120MM guide camera
PHD2 Multistar guiding ( total error avg 0.55 to 0.80 arc sec )
Antlia 3nm SHO Filters
Ha 155 x 180 sec subs up
Oiii 87 x 180 sec subs
Sii 75 x 180 sec subs
Dithered every Sub
Total integration 15.5 hours
Full calibration suite
Darks frames from Library
Flats SHO
Flat Darks SHO
Data Analysed , Calibrated, Stacked and Aligned in ASTAP
Processed in Startools V1.8 via Compose L + Synthetic L from RGB , RGB
In Colour module I used the SHO / HST preset with the following Matrix blend ( 50Sii + 50 Ha , 50Ha + 50 Oiii , 100 Oiii ) followed by adjustments of saturation and colour bias.

Astrobin link for full resolution …..,

https://www.astrobin.com/b09g3e/

Attached reduced file size jpeg


Thanks for looking

Comments welcome

Martin

That's really cool - thanks for posting! Given that it is not completely out of reach of us northerners, I guess the reason it gets so little attention is because the Lagoon is what everyone images instead.

It's not *technically* out of reach for me, but it might as well be. My southern sky is blocked by houses and trees, so I'd have to go remote. In which case I's probably image the Lagoon

Thanks for your reply
Although very close to the Lagoon, this nebula is rarely presented in our local forums , even in the Southern Hemisphere.
In hindsight I should have applied SV Decon to expose more of the fainter structures, in addition to slightly more colour saturation as it composition is quite “fuzzy”
I did try a simulated LRGB Spectrum version using Ivo’s / Guy’s technique creating channels with SHO data only , but it didn’t offer a meaningful result.
I may reprocess at some stage and see if improvement can be achieved
Thanks again
Clear Skies
Martin