Lorenzo Comolli's Astronomy HomePage

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This nebula in Cepheus is very faint and I've found to be a hard subject for my DSLR, even if I had gathered a long exposure under a dark sky. Heavy noise is unfortunately present, expecially in the blue channel. The main red part of the nebula is catalogued as a Sharpless object, Sh2-155, or LBN 527. The blue part below is VdB-155. A couple of the small nebulas on the lower-center border are GN 22.54.1.01 and GN 22.55.2. Many dark nebulas are present, the main ones are LDN 1218 (at left of Cave) and LDN 1215 (at right).
A new improved Cave is here.

Technical Data
Optics	TEC 140
Focal Length	1011 mm
Focal Ratio	f/7.2
Exposure Time	4h20m (single exp of 10 min)
CCD	Canon EOS 5D with Baader filter
Sensitivity	800 ISO
Location	Colle dell'Agnello (CN, Italian Alps) at 2700 m height
Date	18 August 2012
Mount	Gemini G-41
Tracking	Lodestar on an 80mm f/5 refractor
Temperature and humidity	T= +14°C, RH=40-60%
Sky brightness at zenith (with SQM-L)	21.4-21.5 mag/arcsec^2
Notes	Very faint object. Heavy noise due to the faintness and maybe also to the high temperature (very hot month even at high altitude).