Ced 122 - Ha Region in Centaurus

[Ryderscope]

This is an area of Ha nearby to the Coalsack nebula and Crux taken with my widefield rig using the ASI6200 camera and Canon EF200 lens. Approximately 22 hours of data in LRGB and Ha. Full acquisition details can be found in the Astrobin post.

Cederblad 122 is included in a catalogue published in 1946 by Sven Cederblad containing 215 objects including diffuse galactic nebulae. I stumbled across this area when wandering around Stellarium looking for my next imaging target. What I didn't realise until I was processing the data and conducting further research, was that I was imaging part of the "Coalsack Loop" which is a distributed Ha region surrounding the Coalsack Nebula. Mathew Ludgate posted an excellent version of the area in this post here on IIS (https://www.iceinspace.com.au/forum/showthread.php?t=190561&highlight=Coalsack). My attempt is a little to south and east of Mathew's so I am clearly in for a mosaic project to extend the field of view.

RGB images of the area show a very busy star field typical of the Milky Way. However, when adding Ha the field jumps to life with the extended nebulosity. Attached is the thumbnail for the HaLRGB and and the LRGB image to demonstrate this. For the Astrobin post I have included the LRGB image as a mouse over which really shows up the extended Ha nebulosity.

Link to Astrobin post here. (https://astrob.in/gmefjt/0/)
Click on image in Astrobin for higher resolution version.

Comments and critique welcome.

CS,
Rodney

[PKay]

Nice work Rodney.

The mouse over in Astrobin is very interesting, never seen that done before.

Well done :thumbsup:

[hrcoleman66]

Very cool. I always wondered if there was more to see around that area.


Cheers,


Hugh

[Andy01]

Well done Rodney, I've looked at that region many times in an attempt to find a pleasing target for my FOV, but so far I still haven't been able to isolate a frame in that busy area that works for me.
Nice to see the whole thing and the mouseover is very cool! :thumbsup:

[Ryderscope]

Thank you all. There is a lot going on around this area that I reckon will keep me busy for a while yet :)

[Retrograde]

Very nice Rodney - so much going on in this region when it's imaged in depth.

[gregbradley]

I love a good wide lens image and this is a good example. Only critique is it seems a bit dim for 22 hours and could be brightened up a bit.

Greg.

[Ryderscope]

Thanks Pete and Greg for the feedback.

The issue of image brightness is a tough one Greg as it brings into play viewing conditions, monitor brightness and the like. I purchased monitor calibration hardware/software after last year's DMA awards and have made sure to calibrate my monitor (though it is probably time to re check it!).

I do tend to be very cautious about over brightening images as it can lead to loss of subtle detail. Though I agree that this could be a the cost of having an image 'pop' a little more.

To have another look, I went back and tried a few adjustments in Histogram and Curves and thought that maybe, possibly, a small improvement could be made with a very slight contrast curve enhancement. I wasn't convinced enough though I must admit to post another version (though I may change my mind when I ponder a bit more :-).

Thanks again for the feedback.

CS,
Rodney

[matlud]

Great work Rodney capturing this very interesting region. I think it looks bit like a giant arachnid looming over the coal sack! You have done a nice job blending the Ha data in.
Cheers, Mat

[Ryderscope]

Thanks Mat, I can see the the Coal Sack is about to be gobbled up by a giant creature :D

[AstroViking]

Very cool image. I'm always impressed with the work displayed here.


(And yeah, I can see a giant spider in there as well.)