SH2-129 and OU4

[Yoddha]

This object is in my ToDo list for very long time and looking on the list it will still remain there because the result is not the wanted one...

The red nebula is part of SH2-129 known as Flying Bat. The interesting part and the main target of this not so successful project is the nebula OU4, discovered by the French Amateur astrophotographer Nicolas Outters in 2011. It is very faint and requires very serious imaging time. The OU4 (also named the Squid Nebula) is OIII object which is considered as outflow of ionized oxygen emanating from the triple star system HR8119 (located in the center of the frame). Other hypothesis about the OU4 is that it is a planetary nebula. Interesting is that both SH2-129 has no relation between them. The SH2-129 is around 1300 l.y. away from Earth while OU4 is at around 2300 l.y.

Total exposure 9h, the OU4 imaging time is 6h in 15min exposures and is still barely visible!!! Next time will try with at least twice the time, in 20 or even 30min exposures. The revisions A and B are only the OIII channel. 

WO 80FD @ f/5.9, QHY22, Astrodon HII 3nm, OIII 3nm, APT, PHD2, PI, PS

[Guest]

You can see why it was named the "Squid"!

Great work.

[newbie alert]

Seen a few renditions of this target..they all say it's tough...great work on such a faint target..

[Demonperformer]

From what I have read about this object, I would be well-chuffed with getting that result after only six hours of imaging time (in OIII). In addition, I have not seen too many images of it taken with only 80mm aperture. Well worth the effort, I would say.

[Yoddha]

Thank you very much! Your kind words makes me evaluate the image higher in my eyes

[carastro]

You got a better result than I have so far with OU4.  I have only managed to get the bright part of it, not yet succeeded in getting anything like the actual shape of it as yet even doing 1200secs binned.  You at least have the entire shape albeit it faint.

I will probably go back to it at some point and try again.

Well done.

Carole 

 

[don4l]

Well done Ivo.  I tried this a few months ago, and I gave up.  I was wondering if OU4 was an Internet hoax!  I took a 10 minute binned exposure and saw absolutely nothing at all.

 

Carole, well done if you saw anything at all.

[Spitfire]

Hi all,

Ivo, you have done really well getting this image with "just" 6 hours of OIII. Nice image.

I've also tried to image this object (OU4) but without success. I read somewhere that it requires a 3nm OIII filter. As Astrodon is probably the only one who makes this, at £1000+, it is a touch outside my budget! Also, anything below 5nm is incompatible with my Takahashi Epsilon at f2.8. So Carole you did well to get anything with your Baader filters (same as mine).

Geoff

[Yoddha]

Thank you Carole, Don, Geoff!

Definitely it is very faint target... I had to make 10 minutes exposures, binned, stretched to be sure that the squid is there at all... After that followed several exposures rotating the FOV to frame it... Could sound cheap but 10 minutes exposure for framing is something have done for first time ?

Recently I'm used to say that the Astrodon filters are magical I'm lucky to need 1.25" size for my camera and even more lucky to get them on US prices, one of the last samples sold by Don himself... Even in 1.25" size it was serious investment, but they are far superior than the Baader filters that I still have... The OIII is the worst from the Baader set There is something wrong in this filter and all the feedback I have gathered is same, with different samples and different scope systems... 

[coatesg]

This is very good for only 6hrs in [OIII] - it's very delicately presented which goes to enhance the ethereal nature.

If your background levels are already swamping the read noise of the camera, then you might not need to go to 20/30min subs - you'll just need to take a lot more of them (this may help if you're tracking limited or you find subs being ruined...). You're also working at f5.9 - other images I've seen are longer exposures at quicker FRs!

[Allinthehead]

As others have said nice job with such a limited amount of data on a difficult target.

[Yoddha]

Thank you Graeme, Richard!

Graeme, the read out noise is 5e... I'll google how to determine the background to noise relation 15mins definitely are more comfortable exposure than 20/30

 

[MarsG76]

Excellent result... The "squid" shape is definitely visible and I like the subtleness of it against the red Nebulosity. 

[Yoddha]

Many thanks!