Sh2-155, the Cave Nebula

Sh 2-155, known as the Cave Nebula, is a diffuse nebula in Cepheus containing emission nebulosity and dust which shows either as blue reflection nebulae or dark black or brown nebulosity which blocks the light of background stars of our Milky Way galaxy.

Broadband filtered exposures were obtained last May 24th 2025 from Hortezuela de Océn, a dark rural site 150 km away of Madrid (Spain). 

Narrowband filtered exposures (H alpha) were obtained on seven nights (september to november 2025) from my backyard observatory in Pozuelo de Alarcón, close to Madrid.

Equipment:

Takahashi FSQ106N scope. Omegon veTec 571 M camera with a Zwo 7x2" filter wheel with Luminance, Red, Green, Blue, and H alpha filters. Losmandy G11 (Hortezuela) and ASA DDM85 (Pozuelo) equatorial mounts. Seletek Armadillo focuser. PrimaLuceLab Eagle LE control unit.

Software:

NINA and PHD2 for image acquisition. 

PixInsight 1.9,3 with BlurXterminator, NoiseXterminator and StarXterminator plugins, for image processing.