Pinwheel Galaxy is similar to our own homeland Milky Way Galaxy. It has 170 000 light years in diameter (it takes 170 000 years till the light from one side reaches the other) It’s 21 million light years from Solar system and located in constellation Ursa Major (Big Dipper or Great Bear).
This galaxy is characterized by high population of H II regions and therefore I adjusted the image acquisition in the way to highlight it. In total I used four nights to capture this image. The Moon was not bothering and surprisingly, the weather was excellent in first half of May. The first night I used just for luminance channel, second and third one for RGB channels and finally the last one for narrow band image of hydrogen alpha. Ha channel was merged with R channel and therefore the intensity of H II regions was increased. It’s probably my longest total integration time of any galaxy and it was worth it. See for yourself: