Barred spiral galaxies are some of the most interesting galaxies to look at in our night sky. Whilst originally galaxies where just classified as spiral, nowadays we can split these again by calling them either spiral galaxies or barred spiral galaxies, with the obvious difference being the bar in the center of a barred spiral.
As you’d expect, they do have spiral arms at the edge of the galaxy, though they can be affected visually by the bar – this can also affect the motion of the stars in the galaxy too. They make up many of the untold galaxies in our night sky, so let’s learn some interesting facts about barred spiral galaxies.
Barred Spiral Galaxy Facts
- The galaxy that we’re in, the Milky Way, is a barred spiral galaxy.
- The largest barred spiral galaxies in our night sky is known as the Condor galaxy, or NGC 6872. It can be found in the Pavo constellation.
- Another one of the largest spiral galaxies found recently by astronomers is UGC 2885, which astronomers think is the largest in our local universe.
- We know that bars in the center of a galaxy are an indication of the galaxies age.
- We know this after a study of more than 2,000 galaxies revealed that there were far fewer bar spiral galaxies 7 billion years ago, showing that a bar is a sign of maturity.
- We think that it takes approximately 2 billion years for a bar to form in a spiral galaxy.
- There are many spiral galaxies in our universe, with approximately 60% of these being barred spiral galaxies.
- Barred spiral galaxies are classified as a SB, to differentiate them from other galaxies.
- Barred spiral galaxies were discovered by Edwin Hubble whom the Hubble space telescope is named after.
- Barred spiral galaxies are one of four galaxy classifications that we use, along with spiral galaxies, elliptical galaxies and irregular galaxies.
Spiral Galaxy vs Barred Spiral Galaxy – What’s the Difference?
A barred spiral galaxy is very similar to a regular spiral galaxy. The difference? Well, a barred spiral galaxy has a big bar of stars across the center of the spiral. These bars in the center of the galaxy can have a big effect on the movement of stars, as well as affecting the arms of the spiral too.
After a study of spiral galaxies all the way back in 2008, we know that having a bar in its center is a sign that the galaxy has reached full maturity, meaning that bar spiral galaxies are the older galaxies.
Common Questions about Barred Spiral Galaxies
How is the bar formed in a bar spiral galaxy?
If barred spirals are so different from regular spiral galaxies, how do the bars even get there? Well, it’s important to understand that the bar part of a spiral galaxy isn’t a solid object – it’s just a region with a very high density of stars, giving this appearance. The bar is formed by the appearance of the unstable stars at the center of the galaxy, which give a longer bar-like appearance than a regular star.
Why is the Milky Way a barred spiral galaxy?
A barred spiral galaxy is just the name that we have for the appearance of a galaxy, with a bar in it’s center. It just so happens that the Milky Way, where our solar system is located, is a barred spiral galaxy. We can tell this through several different things, from the dust content and color of our galaxy, to the velocity of the stars.
Is the Andromeda Galaxy a barred spiral galaxy?
The Andromeda galaxy, also known as Messier 31, is also a barrel spiral galaxy. It is around 2 and a half million light years from the Earth, and it is the nearest galaxy to ours, the Milky Way.
How many barred spiral galaxies are there?
It’s impossible for us to know how many barred spiral galaxies there are in the universe, because they are just named this based on their appearance and composition. There are trillions of different galaxies in our universe, and we can only see a mere fraction of them.
What are barred spiral galaxy classifications?
The broad classification we use for these types of galaxies is SB. However, we then break this down even further, into categories like SBa (which is a barred spiral that has very tightly bound arms ) and SBc (which is barred spirals that have loosely bound arms).
Barred spiral galaxies are interesting, particularly because we don’t know everything about them. Whilst we know why they are formed and how they’re different to spiral galaxies, there is still much for us to learn about the barred spiral galaxy.