M31 - Andromeda Galaxy. I have added some RGB data to the luminance data, I was hoping to get some more Ha data tonight but there was too much cloud (not in the forecast), this is a total of 9 hours of exposure time. M31 is the closest galaxy to our own at 2,500,000 light years away so this picture is what the galaxy looked like 2,500,000 years ago. It is moving towards us and it is estimated that it will merge with our galaxy in about 5,000,000,000 years (a date to put in your diary)