RASA 8 is back: Iris Nebula chased by some dark nebulosity

[gorann]

After being clouded in forever, it finally cleared and I got as much going as I could (barely) handle. So as I was shooting away on NGC6914 with my double Esprit rig in obsy 1 (posted earlier today), I got the RASA 8 up and running again on my old NEQ6 in obsy 3, aimed at some dark nebulosity near the Iris nebula. Had the ASI2600MC set at gain 100 and -10°C. Got 235 x 2 min so 7.8 hours, which is a lot of photons at f/2. Took a few hours to stack in PI. Most processing done in PS.

I think there is same drama in the image where dark forces appear to head toward the loverly Iris. I believe that nasty bunch are also known as LDN1152, LDN1148, LDN1158 and LBN468

 

[andrew s]

Beautiful image @gorann, fantastic colour. Regards Andrew 

[mackiedlm]

That's a stunning image. Fantastic detail.

Edited October 15, 2020 by mackiedlm

[gorann]

17 minutes ago, andrew s said:

Beautiful image @gorann, fantastic colour. Regards Andrew 

Thanks a lot Andrew! Yes I am pleased about how it turned out. Maybe it is the amount of photons the RASA collects (7.8 hours at f/2 corresponds theoretically to 96 hours af f/7) that makes the "dark" nebulosity look quite bright.

[gorann]

3 minutes ago, mackiedlm said:

That's a stunning image. Fantastic detail.

Thanks Mackie, much appreciated!

[John Nodding]

😱 wow!
 

Noddy

[gorann]

30 minutes ago, John Nodding said:

😱 wow!
 

Noddy

Thanks Noddy!

[Erling G-P]

Absolutely amazing image!

[Pryce]

This part of the image really captured my attention.  Its absolutely beautiful.  Do you know it's designation?

Edited October 16, 2020 by Pryce

[tooth_dr]

5 hours ago, Pryce said:

This part of the image really captured my attention.  Its absolutely beautiful.  Do you know it's designation?

That’s the Iris Nebula. 

[johngm]

@Pryce

Its the Iris Nebula, NGC 7023

 

[gorann]

11 hours ago, Erling G-P said:

Absolutely amazing image!

Thans a lot Erling, you are too kind!

[gorann]

9 hours ago, Pryce said:

This part of the image really captured my attention.  Its absolutely beautiful.  Do you know it's designation?

Thanks Pryce! Yes it is the Iris Nebula and it is always nice to see but also often imaged. So I am actually this time most proud of the other structures captured in this image. They are much fainter and relatively rarely imaged. To bring them out I had to selectively enhance them (in curves in PS) while protecting the Iris from being blown out.

[tomato]

A stunning result, the RASA 8 and the IMX571 OSC is really delivering. Mine is sitting in the box waiting for my dual rig mosaic to be finished...

 

[Skipper Billy]

That's a cracker. Rather you than me focusing at f2 !!  

Chapeau - well done.

[The Admiral]

18 hours ago, gorann said:

After being clouded in forever, it finally cleared and I got as much going as I could (barely) handle. So as I was shooting away on NGC6914 with my double Esprit rig in obsy 1 (posted earlier today), I got the RASA 8 up and running again on my old NEQ6 in obsy 3, aimed at some dark nebulosity near the Iris nebula. Had the ASI2600MC set at gain 100 and -10°C. Got 235 x 2 min so 7.8 hours, which is a lot of photons at f/2. Took a few hours to stack in PI. Most processing done in PS.

I think there is same drama in the image where dark forces appear to head toward the loverly Iris. I believe that nasty bunch are also known as LDN1152, LDN1148, LDN1158 and LBN468

Absolutely stunning! There's no doubt that photon count is king (so long as they're not from light pollution of course )

Ian

Edited October 16, 2020 by The Admiral

[alan potts]

Superb capture Goran, one framed like this I have not seen before. I am no expert, as you well know, but I would say your processing was excellent too.

Alan

[gorann]

4 hours ago, tomato said:

A stunning result, the RASA 8 and the IMX571 OSC is really delivering. Mine is sitting in the box waiting for my dual rig mosaic to be finished...

 

Thanks! You are in for a treat!

[gorann]

3 hours ago, Skipper Billy said:

That's a cracker. Rather you than me focusing at f2 !!  

Chapeau - well done.

Thanks! Actually focussing on the RASA 8 is dead easy and it has so far kept it all night. No need whatsoever to buy any fancy Feather Touch for electronic focuser. I think that they put the system of the super expensive (15,000 GBP)  RASA 14 into it and the mirror is not weighing that much so it was easily done. The problem child is the RASA 11 which at least in its original version had a very floppy mirrior design.

[gorann]

3 hours ago, The Admiral said:

Absolutely stunning! There's no doubt that photon count is king (so long as they're not from light pollution of course )

Ian

Yes, I was extremely surprised how bright what supposedly should be dark nebulosity turned out. I think it may have to do with the amout of photons this scope is collecting in relation to the chip (24 x 18 mm) I am using. My 7.8 hours at f/2 corresponds theoretically to 95 hours at f/7! And yes, equally important, I have a Bortle 2 sky.

Edited October 16, 2020 by gorann

[The Admiral]

9 minutes ago, gorann said:

I have a Bortle 2 sky.

One can only dream!

Ian

[gorann]

21 minutes ago, The Admiral said:

One can only dream!

Ian

Hurry up Admiral - you have two month left to move to wherever you like in Europe😁

Edited October 16, 2020 by gorann

[ollypenrice]

I think your orientation is north-down? Is that right? (No reason why it shouldn't be!)

What struck me about this image, which is a very striking one, is the intensity of the contrasts. The background sky is held down and the reflecting and scattering dust is relatively bright, which emphasizes the shapes in the dusty structures. It really is very forceful and impressive in that way. The blue components in the Iris also extend more widely than we usually see. Both the imaging system and the processing have, I think, brought something new to the target.

I have a couple of reservations, which I only mention because this is such a memorable image. The resolution into the core of the Iris could be better at this image scale. The progenitor star is saturating the area around it. And there are some faint pinks near the core, probably from Ha, which we are not seeing.

What I take away from this image, and what I don't know how you achieved, is the intensity of contrast in the low brightness regions. That is spectacular.

20 hours ago, gorann said:

Thanks a lot Andrew! Yes I am pleased about how it turned out. Maybe it is the amount of photons the RASA collects (7.8 hours at f/2 corresponds theoretically to 96 hours af f/7) that makes the "dark" nebulosity look quite bright.

Now you know what I'm going to say to that! 🤣  How did the photons entering your objective know the focal length of the system that followed? What matters is aperture and pixel size. F ratio is hot air. You proved this with your Liverpool Telescope images!

Olly

[The Admiral]

7 minutes ago, gorann said:

Hurry up Admiral - you have two month left to move to wherever you like in Europe😁

Groan! I'd rather not think about what is happening to this country. My blood pressure is raised enough already 😭.

Ian

[gorann]

4 minutes ago, ollypenrice said:

I think your orientation is north-down? Is that right? (No reason why it shouldn't be!)

What struck me about this image, which is a very striking one, is the intensity of the contrasts. The background sky is held down and the reflecting and scattering dust is relatively bright, which emphasizes the shapes in the dusty structures. It really is very forceful and impressive in that way. The blue components in the Iris also extend more widely than we usually see. Both the imaging system and the processing have, I think, brought something new to the target.

I have a couple of reservations, which I only mention because this is such a memorable image. The resolution into the core of the Iris could be better at this image scale. The progenitor star is saturating the area around it. And there are some faint pinks near the core, probably from Ha, which we are not seeing.

What I take away from this image, and what I don't know how you achieved, is the intensity of contrast in the low brightness regions. That is spectacular.

Now you know what I'm going to say to that! 🤣  How did the photons entering your objective know the focal length of the system that followed? What matters is aperture and pixel size. F ratio is hot air. You proved this with your Liverpool Telescope images!

Olly

Hi Olly,

I am in the middle of the Friday night dinner so this is a short response. The 400 mm FL does not give super resolution to the Iris so I could allways add that later from old data I have. And seeing was not the best and the scope is not on my Mesu but on a NEQ6, so I was tempted to add old data to the Iris. But what I think is amazing is how deep you can ho with this sytem in just 8 hours. I really had to suppress some of the faint stuff not to overwhelm the image with dust - it could have been so much more dusty.