Lorenzo Comolli's Astronomy HomePage

Click on the image for a high res version. MOUSE OVER for H-alpha only. Look also to the H-alpha only hires.

Sh2-101 is a faint nebula only 45' east of Eta Cygni. This image is an Ha-RGB composition, with most of the exposure focused on H-alpha emission (6h) and only a few LRGB (3h50min). Be sure to look not only to the color version but also to the black and white Ha only version.
Note about processing: this image has been co-processed by Edoardo Radice with PixInsight and by Lorenzo Comolli with Photoshop. Thanks Edo for the collaboration!

Technical Data
Optics	TEC 140
Focal Length	1011 mm
Focal Ratio	f/7.2
Exposure Time	Total 9 h 50 min, composed of Ha 6 h, LRGB 140:30:30:30 min (single exp of 30 min for Ha, 10 min for LRGB)
CCD	SBIG STL-11000M @-30°C
Location	Colle dell'Agnello (CN, Italian Alps) at 2700 m height
Date	17-19-20 August 2015 (three nights, partially clouded)
Mount	Gemini G-41
Tracking	Lodestar on an 80mm f/5 refractor
Temperature and humidity	T= (+3 to +7) °C, RH=(80 to 100) %
Sky brightness at zenith (with SQM-L)	(21.2 to 21.6) mag/arcsec^2
Notes	Many clouds interrupted the imaging sessions and only 10 h of total exposure were gathered in three nights, the only usable of the whole week in the refuge.