The Cave Nebula Sh2-155 in Sii-gilded HOOLRGB

About the Object

The so-called Cave nebula Sh2-155 is a diffuse nebula in the constellation of Cepheus,  containing emission, reflection, and dark nebulosity.

Observation Notes

Sh2-155 is a challenging object to process, as the blue reflection nebula are not caught by the Oiii image, so one really needs to blend an RGB image (not only the stars) with the narrowband image. I proceeded in a sequence blending the starless RGB with Ha, followed by Sii followed by Oiii, followed by RGB stars

data were taken on 2024 September 20, 21, 22, and 29

Technical Details

View the full-resolution image together with complete acquisition and processing details on AstroBin.