Dumbbell Nebula - RGB-HOO

[alexbb]

Even before getting my hands on the Celestron C9.25 I started planning to shoot again the Dumbbell Nebula from dark skies this time.

Said and done, at the AstROmania astrocamp this summer I shot 10h of Ha and 10h of OIII (and 2h of SII, but I didn't use them so far) to which I added 3x1h for each RGB from a decent dark place nearby home.

The mount recently started to track worse and worse, but PHD + the new PEC kept things under control.

I also had available around 30h of narrowband and 6h of RGB taken from home 2 years ago with the 200/1200 newtonian and all these were combined in a smaller amount with the new data.

For the highlights I only used the crisper data I had available so I hope I didn't compromise too much on the details. The SCT or the reducer makes the stars a bit softer. Perhaps a new one should be considered...

So, for a total of more than 50h, the Dumbbell Nebula, around 1"/px. Click on it for a better view or visit the astrobin link for full resolution and other acquisition details.

Clear skies!

Alex

[tomato]

A gloriously deep Dumbbell, great image👍

[Dummy]

Wow..

Wish I had the means, opportunity and knowledge to take such photographs. Hope this isn't a stupid question, but can you tell how dark the sky was where you took that picture?

I mean, magnitude-wise 😅

I've been to the darkest place I could find in my country and I could barely see Andromeda..

[alexbb]

46 minutes ago, tomato said:

A gloriously deep Dumbbell, great image👍

42 minutes ago, Dummy said:

Wow..

Wish I had the means, opportunity and knowledge to take such photographs.

Thank you!

42 minutes ago, Dummy said:

Hope this isn't a stupid question, but can you tell how dark the sky was where you took that picture?

I mean, magnitude-wise 😅

I've been to the darkest place I could find in my country and I could barely see Andromeda..

As I described, it was done from different places, multiple years. But at the darkest where I gathered the 20h of narrowband with the C9.25 we measured 21.7-21.8 SQM, that meaning a 6+ magnitude naked eye or Bortle 2.

Closer to home - half an hour drive - we have a decent dark place, Bortle 3, we can see villages' glow at horizon or the 300k+ inhabitants city at ~30km lighting the vest sky. But at zenith we measure >21.4 SQM, usually 21.5+. A 6 magnitude can also be visible from here.

Andromeda is easily visible from a rural sky. When at zenith and the sky is clear and frozen, I can see it even from the city sky if there are no close direct lights in my line of sight.

Edited September 24, 2021 by alexbb

[Mike73]

What an absolutely cracking M27 all that integration time was completely worth it. A real treat for the eyes this, well done!

[CloudMagnet]

Wow, well worth putting the time into this, should really rename it the Bowtie Nebula seeing it like that!

[Dummy]

3 hours ago, alexbb said:

As I described, it was done from different places, multiple years. But at the darkest where I gathered the 20h of narrowband with the C9.25 we measured 21.7-21.8 SQM, that meaning a 6+ magnitude naked eye or Bortle 2.

Closer to home - half an hour drive - we have a decent dark place, Bortle 3, we can see villages' glow at horizon or the 300k+ inhabitants city at ~30km lighting the vest sky. But at zenith we measure >21.4 SQM, usually 21.5+. A 6 magnitude can also be visible from here.

Andromeda is easily visible from a rural sky. When at zenith and the sky is clear and frozen, I can see it even from the city sky if there are no close direct lights in my line of sight.

Oh well, in that case I guess where I thought was really dark here, which is about 3 4 hours drive, wasn't all that dark 😅. According to a light pollution map I saw before, it was supposed to be something like a 5~6 magnitude area. I remember seeing Andromeda with my eyes like a really big oval smudge, and even that was when I was looking at it indirectly. You know, looking at something near it. Through my scope was barely any better. I could just make out the brighter inner part, but not much beyond that.

If what you say is true then I'm guessing my Celestron 130 newtonian is no good, they sky weren't all that dark or something was wrong with my eyesight\glasses.

Good to know though, thanks for the information.

[assouptro]

Stunning!

Bryan

[alexbb]

Many thanks to all of you again!

On 24/09/2021 at 23:52, Dummy said:

Oh well, in that case I guess where I thought was really dark here, which is about 3 4 hours drive, wasn't all that dark 😅. According to a light pollution map I saw before, it was supposed to be something like a 5~6 magnitude area. I remember seeing Andromeda with my eyes like a really big oval smudge, and even that was when I was looking at it indirectly. You know, looking at something near it. Through my scope was barely any better. I could just make out the brighter inner part, but not much beyond that.

If what you say is true then I'm guessing my Celestron 130 newtonian is no good, they sky weren't all that dark or something was wrong with my eyesight\glasses.

Good to know though, thanks for the information.

Here's a good correspondence between Bortle scale, NELM, SQM and what's expected to be seen: https://en.wikipedia.org/wiki/Bortle_scale