The above image was obtained on 5/30/2010, with a Canon 40D attached to a equatorial fork mounted 10" Schmidt Cassegrain telescope. This was a series of 35x120 second exposures W/8 darks, @ISO 800 - A 6.3 focal reducer was used in the optical train along with an Astonomik LP filter. All calibrated and stacked in DSS. 
M51, the 'Whirlpool Galaxy' in Canes Venatici. It was discovered by Messier in 1773. Its companion galaxy, NGC 5195, is a spectacular example of interacting galaxies, in this case NGC 5195 is being "ripped apart" by the huge gravitational disturbance of M51. The distance of M51 is estimated to be about 37 million light years. The diameter is approximately 100,000 light years and the total mass is estimated to be the equivalent of 160 billion suns.
