NGC 7023 -The Iris Nebula
Date: Oct 29, 2019
Cosgrove’s Cosmos Catalog ➤#0015
NGC 7023 - the Iris Nebula (click to enlarge)
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About the Target
NGC 7023, also known as the Iris Nebula, is located in the constellation Cepheus and is only 1300 light-years away. NGC 7023 is actually the small cluster of stars in the nebula center - these stars are surrounded by both emission and dark nebulae.
About the Project
I like the effect you get with this nebula as there are many dark clouds as dark clouds, and in some cases, these clouds are back-illuminated. I was surprised that we had a clear night last night - it was originally forecasted to be cloudy. This is a key week for Astrophotography as the moon is new, so I could not miss an opportunity to go after this object. The plan was to capture 65 x 180-second exposures. Alas, I was hit by some high-level clouds at exposure 35, and I had to shut down. This image is a little wanting in signal-to-noise because of this. The next clear night we have, I will capture this again and stack the entire set. I will post an update when I have it.
Comments on 08/01/21 as this was added to the Website.
First, a little self-critique. A lot of my write-ups - especially early on - focus on what my plan was how those nasty clouds came and messed things up, and my project no longer has the subs it needs. I clearly have to stop that. We live in an area of variable weather, and that’s just the way it is. I really need to surprise when I get a completely clear night rather than be disappointed when clouds move.
I should comment on the image quality here. First - I really do have too few subs here, and it shows in the noise seen in the dark clouds. Secondly, the focus does not seem very crisp - everything comes off just a little soft. Finally - the diffraction spikes on some stars - what can I say - early on, I thought that this makes the images seem more photogenic. I had a photoshop plug-in that allows me to add them - so I did. Fortunately, this phase was short-lived, and I stop doing that. What was I thinking!?
The Annotated Image
This annotated image of the Iris Nebula was created by using Pixinsight’s ImageSolver and AnnotateImage Scripts.
The Location in the Sky
IAU/Sky & Telescope Constellation Map of Cepheus - with NGC 7023 marked by the yellow arrow.
Capture Hardware
Scope: Astrophysics 130mm Starfire F/8.35 APO Scope: William Optics 132mm f/7.0 FLT APO
Guide Scope: Sharpstar 61EDPHII
Camera: ZWO ASI1600mm-pro with ZWO Filter wheel with ZWO LRGB filter set,
and Astronomiks 6nm Narrowband filter set
Guide Camera: ZWO ASI290Mini
Focus Motor: Pegasus Astro Focus Cube 2
Camera Rotator: Pegasus Astro Falcon
Mount: Ioptron CEM60
Polar Alignment: Polemaster camera
Software
Capture Software: PHD2 Guider, Sequence Generator Pro controller
Image Processing: Deepsky Stacker, Pixinsight, Photoshop - assisted by Coffee, extensive processing indecision and second-guessing, editor regret and much swearing….
During August and September I was out shooting every clear night. I had learned a lot of things but I was also noticing several issues that were causing me problems as I did more imaging. I decided to do something to address those issues….