How Many Types of Galaxies are there in the Universe? Check the Names

Galaxies are huge groups of stars, gas, dust and dark matter held together by gravity. Our Solar System is part of the Milky Way, which is just one among trillions of galaxies in the universe. Each galaxy looks different and has its own structure, size, and features.

What is a Galaxy?

A galaxy is a massive system made up of billions or even trillions of stars. Along with stars, galaxies also contain gas, dust, and glowing clouds called nebulae. All these are held together by gravity. Some galaxies are bright and active, while others are quiet and filled with older stars.

Hubble’s Galaxy Classification

In 1926, Edwin Hubble created a simple way to classify galaxies based on how they look. This system is called the Hubble Tuning Fork Diagram. It divides galaxies into three main types:

• Elliptical galaxies
• Spiral galaxies (including barred spirals)
• Irregular galaxies

There is also a middle type called lenticular galaxies.

Spiral Galaxies

Spiral galaxies are the most beautiful and common types. They have a bright center and long, curved arms. These arms contain gas and dust where new stars are formed.

There are two main kinds:

• Normal spirals: no bar in the center
• Barred spirals: have a bar-shaped structure in the middle

Our Milky Way is a barred spiral galaxy. Another famous example is the Andromeda Galaxy.

Elliptical Galaxies

Elliptical galaxies are smooth and round or oval in shape. They do not have arms like spiral galaxies. These galaxies mostly contain old stars and very little gas or dust.

Because of this, new stars are rarely formed in them. A well-known example is Messier 87.

Irregular Galaxies

Irregular galaxies do not have a fixed shape. They look messy and uneven. This usually happens because of collection or strong gravitational forces from nearby galaxies.

These galaxies are rich in gas and dust, so they produce many new stars. Examples include the Large Magellanic Cloud and Small Magellanic Cloud.

Lenticular Galaxies

Lenticular galaxies are a mix of spiral and elliptical galaxies. They have a central bulge and a flat disk like spirals but do not have spiral arms. They also have very little gas, so star formation is low.

Dwarf and Special Galaxies

Most galaxies in the universe are actually dwarf galaxies, which are small and faint. They often orbit larger galaxies.

There are also special types of galaxies:

• Peculiar galaxies: unusual shapes due to collisions
• Active galaxies: powered by supermassive black holes (like quasars)

How many Glaciers are there?

Scientists estimate that there are around 2 trillion galaxies in the observable universe. These galaxies are found in groups, clusters, and large empty regions called voids.