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Contains:  NGC 7023
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NGC7023 The Iris Nebula, 


NGC7023 The Iris Nebula
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NGC7023 The Iris Nebula

Technical card

Resolution: 3245x2411

Dates:Sept. 1, 2019Sept. 2, 2019Sept. 3, 2019Sept. 4, 2019Sept. 5, 2019Sept. 18, 2019

Astronomik B 1.25" Type IIc: 32x600" -10C bin 1x1
Astronomik G 1.25" Type IIc: 32x600" -10C bin 1x1
Astronomik L 1.25" Type IIc: 60x30" -10C bin 1x1
Astronomik L 1.25" Type IIc: 67x600" -10C bin 1x1
Astronomik R 1.25" Type IIc: 32x600" -10C bin 1x1

Integration: 27.7 hours

Darks: ~30

Flats: ~30

Flat darks: 0

Bias: ~100

Avg. Moon age: 6.96 days

Avg. Moon phase: 33.70%

Bortle Dark-Sky Scale: None

Mean SQM: None

Mean FWHM: None

Temperature: None

Basic astrometry details job: 2928298

RA center: 21h 1' 16"

DEC center: +68° 9' 14"

Pixel scale: 0.510 arcsec/pixel

Orientation: 358.608 degrees

Field radius: 0.286 degrees

Locations: Lighthouse Observatory, Burleson, Texas, United States

Data source: Backyard


The Iris Nebula, also NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus. NGC 7023 is actually the cluster within the nebula, LBN 487, and the nebula is lit by a magnitude +7 star, SAO 19158. It shines at magnitude +6.8. It is located near the Mira-type variable star T Cephei, and near the bright magnitude +3.23 variable star Beta Cephei (Alphirk). It lies 1,300 light-years away and is six light-years across. [Source: Wikipedia]

CAPTURE Information:
The image was captured with the iOptron CEM120 mount , the venerable Meade 12"LX200 SCT, and my Atik 383L+ m CCD at F7.16 (2182mm FL). Image subs were taken through Astronomik's broadband filters L, R, G and B. Subs were done at 1x1 bin, -10C, at 10 minutes for L (luminance), and also for R, G and B. Additional L subs were taken at 30s to manage the extremely bright area in the heart of the nebula.

IMAGE information -- 2019:
Lum: 67 subs at 600s (11.17hr) on Sep 1st, 2nd, 4th, 5th and 18th.
Lum: 60 subs at 30s (0.50hr) on Sep 18th.
Red: 32 subs (5.33hr) on Sep 3rd and 5th.
Green: 32 subs (5.33hr) on Sep 4th and 5th.
Blue: 32 subs (5.33hr) on Sep 2nd, 3rd, and 5th.

Processing was done with PixInsight, following (for the most part) kayronjm's tutorial of Feb. 24th. Only L was used to develop the Luminance image. R, G and B were collected for the color mix.
North is to the right (I think), and this is a slight crop due to the misalignment accumulation from so many different filters and times.

I thought this came out fairly well. It's a large nebula with lots of detail. I struggled a bit with the color which was fairly bland, so I probably pushed it too much (as usual). I had done this same target in Sep 2017 using at the time my Celestron CGE Pro mount, but with the same Meade 12" scope. Can't say that the latest image is that much superior to the 2017 version. So the lesson learned from this is to "not compare to previous work"



License: None (All rights reserved)

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NGC7023 The Iris Nebula,