In the article What is the closest galaxy to the Milky Way? on universetoday.com author Matt Williams reveals the interesting facts about the Canis Major Dwarf galaxy. Many have thought that the Andromeda galaxy was the closest to the Milky Way, but it is the closest spiral galaxy. The Canis Major Dwarf Galaxy is about 25,000 light years from Earth meaning that this galaxy is closer to the solar system than we are to the center of the Milky Way. This galaxy is elliptical in shape and contains over one billion stars, many of which are in the Red Giant phase in their lives. There is a trail of stars behind the galaxy forming a ring like structure, otherwise referred to as the Monoceros Ring. These rings wrap around the galaxy three times. It was while investigating these rings did Astronomers discover the Canis Major Dwarf Galaxy. One theory is that the Milky Way swallowed it up.
This discovery of this galaxy has produced a theory that galaxies may grow in size by merging and swallowing their much smaller neighbors. The Milky Way has become the size it is today by swallowing up its neighbors, like the Canis Major, and continues to do just that today. Since the Canis Major stars are already a part of the Milky Way, it is by definition the closest galaxy to our solar system. Many Astronomers believe that the Canis Major is being pulled apart by the much more massive gravitational pull of the Milky Way. The main body of the Canis Major is already drastically degraded and that the rest will soon be completely accredited. They say that eventually the one billion stars of the Canis Major will be added to the 200 to 400 billion stars in our galaxy.
This article relates to our class and the conceptual objective, “I can compare the Milky Way Galaxy to other galaxies.” From our notes we have learned that there are several different classifications of galaxies, including spiral, elliptical, irregular and barred spiral galaxy. This article says that the Canis Major is an elliptical galaxy. The Milky Way, which is a spiral galaxy, is in the process of merging with the much smaller Canis Major. When galaxies merge, there typically aren’t much collisions between stars, mainly because they are so far apart. When the Milky Way completely swallows up the Canis Major, it will just continue to grow in size.
I was fascinated reading this article. I have wondered what would happen if two galaxies collided. Would there be massive explosions? Would the different dust and gases from each galaxy merging be catastrophic? After reading this I have learned that our own Milky Way is already merging with another galaxy. It isn’t violent and it creates opportunities for new stars to form. Overall, I enjoyed this article.