RCW86 supernova remnant in NB 56hrs

[Bassnut]

Hi Guys

Its been a while since I posted a pic.Click here for large (https://fredsastro.smugmug.com/Photography/Astrophotography-1/i-TkDXW5c/A).

RCW86 is one of the brightest SNRs observed in X-Rays in our Galaxy

It has been a bit difficult to capture and process, not a common target.
The Palette ended up being an odd Ha.Ha.SII.OIII mapped as LRGB.
Colourising channels in PS certainly makes fiddling with palettes much easier.

Taken on an RCOS 10" RC Scope at f9, SBIG STXL6303E Camera and PME mount at itelescopes Siding Spring Observatory.
Processed with CCDstack, Star Tools and Photoshop. 56 hrs Total exposure time.

Ha 30hrs, 40min subs bin1. SII 12hrs 40min subs bin2, OIII 14hrs 40min subs bin2. Short RGB exposures for stars added.

[strongmanmike]

Welcome home Fred :love:

What an intriguing object and we don't see many images of this baby, very cool filaments :thumbsup: The whole complex is quite large, might be a good one to hit with a wider field (but narrow field rules I know)

Your stars are looking like triangles though and corners are soft?..perhaps some mechanical stress somewhere in your OTA/mirror support, flattener spacing?

Mike

[RobF]

Pretty cool. Seem to recall reading up on this one and wondering if worth shooting. Plenty of detail coming through.

[Bassnut]

Thanks Mike. Yes, the stars arnt flash. Most of the star RGB subs are OK but a fair few were effected by wind (the scope, not the stars, I think, who really knows). I should have ditched them (the subs, not the stars, although..........). The soft corners, well, ive struggled with that for a while, the scope is too far away for endless fiddling, I put up with it, dont mind too much. Prolly couldnt fix it anyway.

[Atmos]

The nebula itself is fantastic! It is an area that I believe I have seen before but more likely to be something from Hubble :) Love the colour and fainter extensions that are showing up.

It is suffering from a number of mechanical issues though. The triangular stars are caused by either a pinched primary or secondary mirror (probably primary), there is a LOT of field curvature which is either going to be caused by a spacing error of ~5mm or, on a 10" system, no RC flattener.

Considering that it is from iTelescope.net there isn't anything that you can do about that :P I do have a bit of a gripe with iTelescope.net; for a company that has an entire business model around selling time on various telescopes, most of the data that I have seen come out of it has had issues in one form or another. Whether it be mechanical issues like above or stray light (light leaking into the optical systems) presumably caused by light being on in their facility.

[marc4darkskies]

Very cool Fred and certainly off the beaten track. :thumbsup: I admire your commitment too - 56 hours!! :eyepop:

[Bassnut]

Thanks Rob. Don Goldman had a poke with a 20" and got better detail but only with Ha and OIII. Its a difficult one to colour map.

[Bassnut]

Thanks Colin. I dont always get that star trouble (apart from the corners), my fault. Also, the scope is mine, hosted and installed by me, not for hire, mechanical problems are all my fault and nothing to do with itelescope and yes it is a 10"RC with no flattener, im right on (or over) its chip size limit without a flattener and orthoginality is a bit off, the RC is pretty old.

Geez enough already :P :lol: Ill try harder next time.

[Bassnut]

Thanks Marcus. 56hrs is a bit over the top I know, but I just keep clicking go, not much effort with that, and I sort of need to anyway, its only a 10" :P.

[gregbradley]

That's a new one. Cool colours and a great effort.

Greg.

[Placidus]

Wow, Fred! That's special!

Trish immediately saw the brightest part of the nebula as a bird flying toward us, head and beak pointed toward our left. It's very obvious when you see it.

When I look at a narrowband image, I basically ignore the stars and look at the nebulosity, which is what you took the photo for. The faint extensions are really something. Crisp and clean and beautiful.

The 2x2 binning was obviously necessary. My impression is that despite being an SNR, there's very little SII in the image.

Is it just conceivable that using H-alpha as luminance is concealing some of the SII, particularly further out where there's less H-alpha?

Wonderful work.

Mike

[Atmos]

Oh right :P I just assumed that with it being at their facility it would be theirs hehe Pinched optics typically mean that SOMETHING on either the primary or secondary mirror holdings has been over tightened, basically simulates the astigmatism that I have in my own eyes :lol:

Stars aside, its great! Just happens to be that a good amount of the data that I have seen come out of iTelescope.net (the actual paid part) has had issues of various kinds. Puts a bee in my bonnet :P

[Slawomir]

Interesting and unusual target, awesome effort Fred :thumbsup:

Also, we do not get to see images with such long integration every day :eyepop:

Mike's suggestion of adding SII (and maybe OIII) to Luminance might be worth trying, as it could show more information in the Lum.

[Bassnut]

Thanks Greg



Thanks Mike. Actually OIII was dimmer than SII. SII is green in this image and Ha red. I had a close look at the distribution Ha (red) was everywhere SII and OIII were and extended much further. So I was comfortable with Ha as lum.



Cheers Colin. It doesnt have pinched optics, its just the way I tried to fix the elongated stars. Ive now fixed the stars and updated the image.



Thanks Suavi. The Ha was big enough not to hide S!! and OIII, as far as I could see anyway.

[RickS]

Nice onë, Fred! Reminds me a bit of the "Bug."