Why are galaxies the colors that they are in photographs?


They’re always bright, vibrant colors. What gasses are burning, and whats happening?

In: Chemistry

The color of a star is directly related to how hot it burns. The hotter a star the bluer it appears, the colder a star the redder. Our sun is a G-class star and appears yellow. All stars have energy because their gravity is so intense the nucleus of the atoms of two different elements fuse together the difference of their mass manifests in energy some of which we perceive as light.

Most images you see are colour adjusted by the people making the images. A lot of the light wave they get is outside the visible spectrum for humans, UV and X-rays etc… it makes it make more sense for both scientists and more visually cool for people if its shifted a bit to be in the visible band, showing more contrast and brightness. A lot of very distant stuff just kind of wouldn’t look like anything or be very dull in comparison to surroundings if they left real light levels and colours.

If you see a galaxy through a telescope with the naked eye, it looks more like a dim gray smudge. The vibrant colors only show up when you take a long exposure image.

The color comes mostly from stars, there are so many of them in a galaxy that they all blend together into a blurry glow. There are also interstellar gasses which can be illuminated by starlight or block starlight.