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NGC 7023 – Iris Nebula

NGC 7023, also known as Caldwell 4 or the Iris Nebula, is a bright reflection nebula located in the constellation Cepheus. It lies in a region of the Milky Way rich in cosmic dust, within which the nebula is embedded. It shines at an apparent magnitude of about +6.8 and is mainly illuminated by the central star HD 200775 (V380 Cephei), with a magnitude of +7.4. It is located near the Mira-type variable star T Cephei.

General information

Constellation
Cepheus
Category
Nebulae
Date
23 August 2023

Capture

Total time
4h 35min
Subframes
300s (Ha: 8x, OIII: 22x) bin1; 300s (R: 12x, G: 12x, B: 12x) bin2
Gain / Offset
125 / 30
Calibration
50 library dark frames, 50 flat frames and 50 dark-flat frames, without bias frames

Equipment

Telescope
TS102 f/5.6
Camera
ASI294MM at -10ºC
Filters
CLS, R, G and B Astronomik, 36 mm; Ha and OIII, 6 nm
Mount
HEQ-5 Pro belt drive
Guiding
PHD2, Guide scope 60mm/f4 + ASI224MC + PegasusAstro UCH + PPBMicro
Focuser
ZWO EAF
Filter wheel
ZWO EFW 7pos

Processing and environment

Processing
Stacked and post-processed with PixInsight 1.8.9-3
Acquisition
NINA
Location
l'Ampolla, Tarragona
Sky
Bortle 4

Additional versions

Wide field of viewWide-field view of the star field surrounding NGC 7023, showing its environment within the dusty region of Cepheus.
Stellar environment of NGC 7023Additional field view placing the nebula in context within its nearby stellar environment.
Close-up of NGC 7023Crop of the main nebular region highlighting the reflection structures and dark dust clouds.