Lorenzo Comolli's Astronomy HomePage

Click on the image for a high res version. HIGHLY RECOMMENDED 100% VIEW.

Abell 1185 is a galaxy cluster in Ursa Majoris rich of galaxies, and characterized by the jet of NGC3561, a double galaxy made of the main component (below, mag. 14.7) and NGC3561B (above, mag. 14.3). The largest galaxy is NGC 3550 (mag. 14.2), about 7' west of the jet, with a very interesting triple nucleus. Nearly one hundred of galaxies are imaged here together. Look at the full res image and scroll at 100% resolution all over the image.
This LRGB image has been gathered during two night at Saint Barthelemy.

Here below I show a 100% crop of the central part of the galaxy cluster, and a composition of the best galaxies in the field.

Technical Data
Optics	TEC 140
Focal Length	1011 mm
Focal Ratio	f/7.2
Exposure Time	Total 10 h 40 min, composed of L-RGB 380:70:70:120 min (single exp of 10 min)
CCD	SBIG STL-11000M @-25°C and @-40°C
Location	Saint Barthelemy, Passet (AO, Italian Alps) at 1900 m height
Date	24-25 February 2017 (2 nights)
Mount	Gemini G-41
Tracking	Lodestar on an 80mm f/5 refractor
Temperature and humidity	T= (-4 to -8) °C, RH=(50 to 70) %
Sky brightness at zenith (with SQM-L)	(21.3 to 21.7) mag/arcsec^2
Notes	Very bad seeing on the first night (10" FWHM !!!). A lot of frames has been discarded. Problems with ice on the sensor in the first night, so I limited the cooling to -25°C; then the desiccant was "cooked" in our caravan and the problem disappeared even cooling at -40°C.