Clic here for 70% size 2772x1833 (706 kB)
The Pinwheel Galaxy M101 is revealed as one of the most prominent face on spirals in the sky. While quite symmetric visually and in very short exposures which show only the central region,
it is of remarkable unsymmetry, its core being considerably displaced from the center of the disk. Halton Arp has included M101 as No. 26 in his Catalogue of Peculiar Galaxies as a "Spiral with One Heavy Arm".
105mm TMB refractor with flattener at f/6.5
About this Image
It lies at 24 million light years distance in the constellation of Ursa Major.
Checkout a higher resolution image: here.
A closeup at M101 in 100% size is shown below.
M101 is the brightest of a group of at least 9 galaxies, the brightest companion is the distorted NGC 5474 (type Sc, 10.85 mag vis) to the SSE.
Other probable group members are NGC 5477 NGC 4485, NGC 4486.
A collection of the brightest galaxies in this field including the faint Holmberg IV is shown in the image below in 100% size.
Technical Details
Optics
Mount
MK-100 GEM
Camera
SBIG STL-11000M at -20C, 1x1 bin, internal filter wheel
Filters
Astronomik LRGB
Date
11-19 May 2004.
Location
Wildon/Austria
Sky Conditions
mag 5 sky, medium transparency, temperature 10 C
Exposure
L:R:G:B = 200:30:30:30 minutes (10-minute sub-exposures),
Processing
Image aquisition in Maxim DL 4.0;
Image calibration, aligning, min-max excluding average stacking, color synthesis, DDP in ImagesPlus; color balance, curves in Photoshop; size 19/35/70%;
north is up;