M51 whirlpool galaxy 24, 25, 26 and 27th of April 2011
C8 at F10, SBIG ST-4000XCM -20C 8h20min (50x300sec). Nice quiet weather shooting directly at zenith guiding at 0.2 sec. on the mount.
Light travel time: 37 million years.
As described here: http://www.ancientstarlight.com/M51_VMC.html, this image
captures a mag 20.5 galaxy SDSS J132940 with a redshift of z = 0.257558 corresponding to a distance of about 3 billion (10^9) lightyears.
The galaxy is seen here at center:
Processing: CCDSoft, AstroArt 4.0 cal. and DDE, IRIS gradient removal, PSE 9 adjustments.