Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Semeis 57 - The Propellor Nebula


Jkulin

Recommended Posts

Ever since I saw @steppenwolf beautiful rendition of this nebula I wanted to have a go but wasn't sure I had the skills to do it justice.

I'm due to have Major Surgery on my spine in November/December and will be out of action for possibly up to 6 months, so whatever scope I have on my pier is going to have to remain as I have been advised no lifting whatsoever! So working on that basis and knowing what a pig it is to slide my 10" Truss out of the Losmandy saddle on my mount I have decided to stick with the 2008mm FL rather than change to a smaller magnification when Galaxy Season is in full swing come the new year. So on that basis all of my image captures will be rather closer than some of the gorgeous widefield images that I would liked to have captured.

Thus the reason for doing this at this magnification.

With this in mind, I membered Steve's beautiful version that he did on his Esprit 150. So yesterday afternoon, suddenly appeared as though we might have a few hours clear, so not being one to miss an opportunity I planned the sequence in SGP and waited.

Of late I have been capturing my flats prior to the main imaging commencing as that means I can take advantage of the twilight and get to bed 45 minutes earlier rather than hang around at the end.

So flats duly completed at Binning 1x1 and then the first two 20 min subs down and looking promising, I sent a copy over to my mate Peter Shah via Whatsapp for his view which I always value and his view was that I should be binning at 2x2 or even 3x3 as my image scale was 0.55, so with muttered cursing I cancelled my sequence and started all over again at 2x2, but knowing Peter was right.

As the night progressed the guiding on my mount got better and better down to 0.24 rms with a small patch of poorer seeing, but I managed to get 11 x 1200s Ha subs before sleep and seeing ended play.

The intention is to get 11 x 1200s of OIII and the same with the SII, but until we get further clear nights I decided to process the data I had, I was rather blown away, all I have done is process and calibrate, a very quick stretch (and I mean quick) and a tiny amount of sharpening, nothing else, I recognise that i will need a lot more processing, but as a quickie I'm quite pleased: -

HA_Processed_OnlyV2.thumb.png.34e5dcc9e23645f4569e197cb8085e7d.png

I'm quite sure if I can capture the other channels as nicely then I should produce something respectable so I am posting this as WIP and as and when I get the other channels then will process and post.

iOptron CEM120EC
Moravian G2-8300 MkII
Moravian 7 Postion 2" FW
Lodestar x2 Guide Camera
QHY M OAG
GSO/AA 10" Truss RC
Chroma 3nm Ha 2" Unmounted
Processed with SGP, PHD2 and PI

Thanks for looking.

Edited by Jkulin
typos
  • Like 11
Link to comment
Share on other sites

On 04/10/2019 at 01:07, souls33k3r said:

An absolute belter John. Love this. Can't wait to see the final image. 

Yeah but that Ahmed we need clear skies...chance a be a fine thing!

 

On 04/10/2019 at 01:23, steppenwolf said:

Very nice indeed, John and so lovely and close in! Good luck with the op.

Thanks Steve, appreciate your thoughts.

  • Like 1
Link to comment
Share on other sites

  • 1 month later...

I didn't realise just how hard this was going to be to process, I'm still not convinced I have done this justice. The data seemed good but the stacking was a mare.

No matter how hard I tried to remove the green it just didn't look right without it, so I have left it in, arguing that if the Hubble can have green in the Pillars of Creation, then I can have it in my Propeller...lol

It initially proved a pain to stack and finally a good mate had a look and discovered one light frame just wasn't behaving and once removed then it was fine. For the first time I combined in Pixel Maths which allowed me a little flexibility.

It is what it is and it seems like an eternity ago but was in fact the last time we had any clear skies.

The Ha looked so promising, but just guess I need to keep practising to get it better.

I also experienced for the first time ever hundreds of scattered random red pixels, I have cloned many of them out in PS, but no matter how hard I tried on the stacking they were always present, I did wonder if my new darks library may be to blame, any thoughts would be welcome.

Well this was from the last clear night we had in Mid October, we have got to get a break soon!

Propellor_171119-800.jpg.2a077bbd8e80c60a24c07e72cff5e858.jpg

Link to the full details: - https://www.astrobin.com/b5du3j/?nc=user

 

Edited by Jkulin
typos
Link to comment
Share on other sites

I think you mono Ha image is great--very natural and real looking, with a #D aspect with the dark structures clearly visible in front of the Ha emissions.   I also like the scale--when you click on full resolution you are taken in, and there is no image degradation.  Its great.  I do not think your color versions have matched it in quality.  Take heart--it ain't easy!  this region makes really fine Ha mono images.  As for you color versions--the fist is my favorite--the nebula is clearly part of a larger emission area.  In teh last-that is not as easilly determined.  Now--if you took the propeller structure form #3 and replaced it in #2--that would be spot on I think.  keep working on it.  if you are asking yourself "Is that it?  yeah...I think that's it....right?  and then wondering...it means it isn't it yet.  Only you can judge.  That pebble in your shoe is real (and it won't go away I might add)

Rodd

Link to comment
Share on other sites

Thanks Rod, I have similar thinking as you.

I do wonder if the OIII and SII degraded the Ha because it was a near enough full moon.

I agree about the structure in 2 vs. 3.

It was more than a pebble in my shoe, it was a bloody great boulder!!!

Yeah it is it for now, unfortunately we have not had a clear night in over 5 weeks now, so I fear spending any more time capturing better OIII and SII would be lost time on other targets.

I truly appreciate your thoughts though, thanks.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.