Diversity Of The Universe is a project of an (astro)photography that emerged in summer 2016.
During this summer I made a lot of astrophotos, mainly nebulae :
- The Iris Nebula
- Sharpless 119
- The Heart Nebula
- The North America and Pelican Nebulae
That’s it : This will be my next goal, but It’ll be a tough one.
7 degrees in the sky is a quite large area (14 times the size of the full moon), and despite the tiny 310mm focal length that I’m using, a mosaic was the only way to achieve my goal. I have mixed feelings about mosaics. I made a 9 panel mosaic of Sadr region in 2015, and to be honest it’s been a true challenge and a lot of work to get what I had in mind. In this case a 6 panel mosaic would be sufficient.
As I’m living near a big city (Paris, France), there’s a lot of light pollution in my area. I’m now doing Narrow Band Imaging. It’s useful in polluted areas like mine, but you can only take photos of emission and planetary nebulae. I’ll have to use narrowband and common LRGB filters then combine the images.
One of the objects, the planetary nebula Ou4, is very faint. So faint that it’s been discovered only 5 years ago, in 2011. I wasn’t even sure if I could take a decent picture of it.
So there was those constraints :
- A 6 panel mosaic
- Combine LRGB images with Narrowband images
- At least one very faint object
Then Ou4 became visible on the stacked image (58 x 20mn exposure) :
The Ha filter was used to capture the Sharpless 129 emission nebula. A single night with 36 x 10 mn subs for a total of 6 hours gave me plenty of signal (36 x 10 mn) :
This was the first panel of my image (total exposure 25h20mn), and I published it the 14th september 2016 :
There are two interesting articles about this image (many thanks to the authors):
The mosaic was ok, but I had 5 of the 6 objects that I wanted :
A galaxy, an open cluster, a dark nebula, an emission nebula and a planetary nebula. But the reflexion nebula VdB 140 wasn’t there and I had to make the 3 other panels.
The 4th panel has been made using LRGB and Ha filters. VdB is a reflexion nebula but is also an emission nebula. This panel has been made over two nights (29 sept and 02 oct 2016).
The 2 others panels with “only” stars have been made in LRGB in a single night (3 oct 2016).
In the morning of the 4 october 2016 I had all the images I needed to make my mosaic.
I used PixInsight and Photoshop to make the final image.
9 days later the image was finished. I’m not very pleased with the edges of the panels and there’s a lot of distortion in the image but here it is.
The final image
This image is made of 294 subframes for a total of 46h53mn of exposure. This has been shot over 11 nights.
The gear used was :
- William Optics ZenithStar 66 refractor
- William Optics Flatenner II 0.8x Reducer
- AZ-EQ6 GT mount
- Guiding with a Skywatcher 9×50 finder scope
- Guiding with a QHY5L-IIc camera
- CCD : Moravian G2-8300 with external filter wheel
- Astrodon filters : L,R,G,B Tru-Balance, Ha 5nm, OIII 5nm
This is to my knowledge the first time those 6 objects appears in a single picture.
Those 6 deep sky objects are :
- An open cluster : NGC 6939
- A Galaxy : NGC 6946 , the Fireworks Galaxy
- A Dark Nebula : Barnard 150
- An Emission Nebula : Sharpless 129
- A planetary Nebula : Ou4
- A relfexion nebula : VdB 140
I’m happy to share it with you and hope you’ll like it.
La Diversité de l’Univers est un projet d'(astro)photographie qui a émergé à l’été 2016.
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