Sh2-155 – Cave Nebula

Sh2-155, known as the Cave Nebula, is an emission nebula in the constellation Cepheus. It has an apparent angular size of approximately 50 × 30 arcminutes and a visual magnitude of +7.69. The image combines Ha, OIII and SII emission through an SHO composition using the Hubble palette.

General information

Constellation: Cepheus
Category: Nebulae
Date: 16 December 2023

Capture

Total time: 7h 30min
Subframes: 360s (Ha: 35x, OIII: 18x, SII: 22x) bin1
Gain / Offset: 125 / 30
Calibration: Not specified

Equipment

Telescope: TS102 f/5.6
Camera: ZWO ASI294MM at -10 °C
Filters: Ha, OIII and SII Astronomik, 36 mm and 6 nm
Mount: Sky-Watcher HEQ5 Pro with belt drive
Guiding: Not specified
Focuser: Not specified
Filter wheel: Not specified

Processing and environment

Processing: Stacked and post-processed with PixInsight 1.8.9-2; composició SHO with paleta Hubble and ponderació cromàtica 1,7 SII – Ha – 1,3 OIII; estirament with GHS and ajust del color with SelectiveColorCorrection
Acquisition: NINA
Location: l'Ampolla
Sky: Bortle 4

Additional versions

Wide field of view: Sh2-155 – Cave Nebula — **Wide field of view**Wider view of the star field and nebulosity surrounding Sh2-155.

Foraxx Constant palette version: Sh2-155 – Cave Nebula — **Foraxx Constant palette version**Processing test using the Foraxx Constant palette, created from the HOO and SHO compositions of Sh2-155. After separating the channels with ChannelExtraction, the image was recombined in PixelMath: R = H(HOO) × 0.5 + S(SHO) × 0.5; G = O(HOO) × 0.5 + H(SHO) × 0.5; B = O(HOO) × 0.5 + O(SHO) × 0.5.