Galaxy morphological classification

Think of galaxies like different kinds of cars. Just like how there are different makes and models of cars, there are different types of galaxies out there. And just like how you can tell what kind of car it is just by looking at it, scientists can look at galaxies and tell what type they are based on their shape and features.

Scientists use a system called “morphological classification” to group galaxies into different types. This system looks at a few things:

1. Shape: Just like how cars come in different shapes like sedans, SUVs, and trucks, galaxies have different shapes too. There are three main shapes of galaxies: spirals, ellipticals, and irregulars. Spirals look like a pinwheel with arms that spiral out from the center. Ellipticals are more like blobs or footballs. Irregulars are, well, irregular in shape and don’t fit neatly into either of the other categories.

2. Features: Galaxies also have different features, like the size of their bulge (the central part of the galaxy) or the tightness and number of spirals in the arms. Scientists use these features to further classify galaxies into more specific subtypes.

3. Color: Finally, the color of a galaxy can also be used to classify it. Galaxies that are blue or green usually have a lot of new star formation happening, while galaxies that are red or yellow have mostly old stars and not much new star formation.

All of these factors are used together to determine a galaxy’s morphological classification. Just like how you can look at a car and say, “That’s a sports car,” scientists can look at a galaxy and say, “That’s a spiral galaxy with a tight two-armed structure and a blue color, which means it’s actively forming new stars.”