by Mike Mendoza
In the past few weeks, I have been exploring galaxies and learning a lot about them. To most, there is a common belief that there is only one kind of galaxy and that all galaxies are the same. This, I have learned, is not the case and that every galaxy is unique in its own way but these unique galaxies can be classified into their own categories to show that certain galaxies contain the same properties and can be generalized into a set “type” of galaxy.
While I have been learning about galaxies, I have also been using a citizen science website called Galaxy Zoo in order to help astronomers categorize galaxies. This is done by analyzing an image of a galaxy and then answering questions that describe the image of the galaxy. While doing this, I was starting to realize that the galaxies are a series of different colors. Most of the time the galaxy was either an orange or an off-tone white. As I went through more and more images I started to realize that there were also galaxies that appeared to different shades of blue.
To me, with a previous knowledge of how heat and energy works, I was beginning to think that the difference in color was a matter of energy and heat signals that was being given off of the galaxy. Through research and consulting one of the astronomers that helped develop Galaxy Zoo, I was able to create a hypothesis about the color of the galaxies into simply a matter of component stars and how old they are. Stars that make up the galaxy, as well as debris and dust surround a galaxy and eventually help create it into what we see in the image. All stars give off energy and heat, some look white because they are hot and some look red because they are cooler. Red galaxies contain mostly these red stars, which are older, and blue galaxies contain mostly the white/blue stars which are younger.
screen shots from Galaxy Zoo showing galaxies of different colors
Adler Astro-Journalists 