Andromeda

Andromeda is our nearest neighbor galaxy, only 2.5 million light-years from Earth. Andromeda is 50% larger than our galaxy at 220,000 light-years across, and contains 1 trillion stars, twice as many as Milky Way. On clear dark nights you can see Andromeda as a faint glowing smudge. The red area in the disc are concentrations of hydrogen gas, star forming regions. The blue regions are concentrations of new, young stars, recently ignited. Our galaxy, Milky Way, and Andromeda are on a collision course and will come together in about 4.0 billion years to form a single, giant galaxy. When that happens, the night sky on Earth will be much brighter, illuminated by the light of many more stars. This image combined exposures from both an astro-modified DSLR and a cooled astronomy camera . The color was provided by the DSLR (RGB), while the detailed structure was provided by the cooled astronomy camera (luminance).
 
9.25 hours total exposure