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).

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).