Sharpless 2-235 (Rather obscure target!!) in Ha

[swag72]

In my quest for the obscure targets and something out of the ordinary, my scope settled on Sharpless 2-235 in Auriga for the last couple of nights. Sh2-235 is the kidney shaped nebula in the middle and to the top right is Sh2-232, a larger and feinter circular nebula.

Details:

M: HEQ5

T: SW 120ED Pro x0.85 reducer

C: Atik 314L mono

F: Baader 7nm Ha

G: 9x50 finder with QHY5 - Maxim

23 X 600s (3hr 50mins in total)

Captured in Artemis, processed in PI

No flats, darks or bias as they did odd things in DSS! Focus obtained using Bahtinov Grabber and thanks to you all in a previous thread, it worked well.

Would welcome your comments as you can't always see the wood for the trees when you've been looking at it for ages!!

[Earl]

Have you tried the Image calibration in PI, its not as bad as it looks, the only issue I have is with Flats, which im struggling with since I went to CCD.

I have problems with DSS using a CCD however with my Canon its fine.

[swag72]

As this is the result with no calibration files at all, I'm concentrating on other things at the minute, while I wait for PI to become easier. I did a thread last week or so about PI and Image Calibration files - I'm not sure how good they are. This was stacked in DSS as PI wouldn't touch it and kept giving me an error message.

[James]

...while I wait for PI to become easier...

Hmm. I've been waiting for that but it ain't happening yet! Interesting object, I'd no idea it was there. The only negative I'd say is that the stars are elongated slightly.

There's a lot of detail in there!

James

[swag72]

Cheers James - Looks like I still have the curse of elongated stars - I CAN NOT get rid of them, so just have to live with them!

[ollypenrice]

Cheers James - Looks like I still have the curse of elongated stars - I CAN NOT get rid of them, so just have to live with them!

No you don't! The cause is out there waiting to be found. But that's for another thread and in the meantime you can do a naughty but nice Ps fix, viz;

-Rotate the canvas so that the star elongation is horizontal or vertical.

-Make a copy layer.

-In Layers, select Blend Mode Darken.

-Go into Filter>Other>Offset and choose the axis along which you have the elongation. Plug in a value of 1 or 2 or 3 pixels and apply it. You want to choose a value which over-does the correction slightly. Keep that one, then go into Edit>fade and fade the offset filter till you have.... Taraaaa..... round stars!

-Flatten Image.

Meanwhile, back at your image... I think it's a cracker and is this ever on my list? You bet it is. Many thanks for a new target idea. Splendid object and small for a Sharpless. You've done it proud.

BTW I found with Sharpless 2-129 that I could get away with the scantiest colour, just half an hour per channel from memory. Worth a pop?

Olly

[swag72]

Cheers for that Olly - I am going to have a go now. Await incoming 'HELP!!'

Glad that you like the image - I'm really liking the Sharpless stuff, unfortunately they're not all in CdC. There's another one incoming once the cloud clears!

[AndyUK]

I've not seen or heard of this one before (hardly surprising - If it's not a Messier, NGC or IC then my handset doesn't give me the option!) Did you use EQMOD to find it... Or simply RA/DEC settings? I look forward to seeing some colour on this - It looks VERY interesting indeed...!

[swag72]

Cheers Andy - I found it just ploughing through the Sharpless catalogue and it is in CdC. I note that Olly and you have said about colour - How will I know in advance what kind of colour is in there? I assume that nebulas are generally just red?

[AndyUK]

(Maybe I don't have that catalog installed in CdC... or maybe it's somehow got corrupted - I'll have a look at it later!).

From surfing the net, it appears that this nebula itself is mostly "red" (Ha), but on some of the images I found of this, there appears to be more than a few yellow stars around this region, as well as a few blue ones... and on one image there definitely appears to be something interesting going on at the bottom of the nebula as well as some dark dust clouds knocking about(?) (LINK)

[swag72]

That looks quite interesting Andy - May well give it a go!

I have got a copy of the Sharpless catalogue, but can not get it loaded into CdC - I think it was Ken that suggested that the beta version of CdC is better for loading in these catalogues, but I don't want to be a beta tester!! I'll wait for the update!

[AndyUK]

I have got a copy of the Sharpless catalogue, but can not get it loaded into CdC

Ditto... But I have a spare laptop (and some time!) so I'll upload it and see what the beta looks like at the moment - I see that the latest update was posted up at 5am this morning!

[ollypenrice]

Cheers Andy - I found it just ploughing through the Sharpless catalogue and it is in CdC. I note that Olly and you have said about colour - How will I know in advance what kind of colour is in there? I assume that nebulas are generally just red?

Part of the fun is that you don't! You may get next to nothing, or literally nothing at all of the nebulosity in your RGB layer. The famous Simeis 147 showed absolutely nothing for me in RGB but sang loud and clear in Ha. You just hope for some nice star colours and in Sh2-129 I got lucky with a lovely red-blue pair.

http://ollypenrice.smugmug.com/Photography/Widefield-images-including/i-ZkkMhmM/0/X3/SH2-129-HaRGB-FLYING-BAT-NEB-X3.jpg

For star colour a shortish stack in RGB only can give you the best possible star colour because you don't burn out the centres of the stars with a lum layer.

When you've added Ha to red (I use blend mode lighten) you can put the RGB-only stars image under the HaRGB and carefully erase the stars from the top layer to get true star colour.

Olly

[swag72]

Cheers Olly - The round star trick worked well too!!

[ollypenrice]

I think I got that one from Jordan (JCJC)...

Olly