Explanation:A majestic swirl of millions of suns in the sky apparently extended as half full moon (60,000 light years real) was discovered by the French astronomer Charles Messier in 1773 and added to the number 51 into famous namesake catalog. Besides being a magnificent example of galaxy viewed from the front, Messier 51 is also perhaps one of the finest examples of interacting system. In fact at the end of one of its main arms as captured by a huge octopus tentacle is NGC 5195 (discovered in 1781 by Pierre Mechain), or what remains of a galaxy, now heavily distorted and deformed due to the intense gravitational interaction with the largest partner, so as to form, with those who were his exterior, a giant diffuse halo around M51. The interpenetration of these two objects and compression of huge clouds of molecular hydrogen (seen as beads of dark matter) in them it is giving rise to a large increase in the birth of new star-forming regions (HII regions, as seen in the image red balls extended thousands of light years). .As Most of the galaxies even this presents towards the core, a color tending to yellow or red as predominant in those regions are the stars older, ie closer to the end of their evolutionary process; outward instead it is possible to discern a typical blue color of the light of young, hot stars. The pair is located about 31 million light-years away, near the handle of the Big Dipper, but officially within the boundaries of the small constellation of Canes Venatici.
|Optics:||Celestron C11 @ f6,3 – f10- f20|
|Mount:||Avalon M1 Fast Reverse|
|Camera:||SX H694 unbinning|
|Location:||Viterbo, William Herschel obs.|
|Exposure:||Lum: 13,9 h; Hydrogen: 211 min; Red : 100min; Blue: 165 min; G: R/Bsum of single frames 20-30min.|
|Cooling:||avg – 5°|
|Processing:||Iris, Sequence Generator Pro, AstroArt, CCD sharp, PHD2, PS3|