Spiral Galaxy Facts
SPIRAL GALAXY FACTS
The home of interesting spiral galaxy facts for kids and adults.
Interesting facts about spiral galaxies.
What is an spiral galaxy?
Spiral galaxies are not celestial marvels, they also provide us with some of the best views in Earth's night sky. Some of the best-known galaxies are of the spiral variety and they get their name from their distinctive appearance.
These types of galaxy are named this way because they have a swirl appearance that looks like a spiral, and a little like a ninja throwing star!
10 Facts about spiral galaxies you didn't know.
1. The Milky Way is not a traditional spiral galaxy
Our Milky Way galaxy was considered to be a spiral galaxy until 2005. It wasn't until slightly closer inspection confirmed it was something a little bit different – a barred spiral galaxy. This type of galaxy has a central structure, comprised of stars, that is shaped like a bar.
Did you know?
Bars are found in around half of all observed spiral galaxies
2. Big galaxies are faster than small ones
The larger a given galaxy is, the faster it spins. Large galaxies can spin up to twice as fast as smaller galaxies. Spiral galaxies of the larger variety can spin their 'arms' at an impressive speed of up to 1.25 million miles an hour.
Did you know?
The Milky Way spins at a rate of 130 miles per second.
3. Spiral galaxies can be rather large
One of the larger known spirals galaxies is NGC 6872 – this spiral galaxy is approximately 522,000 light-years across… Which makes it roughly 5 times larger than the Milky Way.
Did you know?
NGC 6872 is also known as the Condor Galaxy and is around 5 billion years old.
4.Spiral galaxies are not the only type of galaxy
Spiral galaxies are one class of galaxies that were originally named ‘galaxy’ by American astronomer Edwin Hubble. He described them in his 1936 writing ‘The Realm of the Nebulae’.
Did you know?
The Hubble Space Telescope was named in honour of Edwin Hubble..
5. Spiral galaxies are armed
Spiral galaxies have arms, which are sites of continual star formation. These sites are brighter than the disk of the galaxy. They are brighter because of the presence of younger stars, known as OB stars.
Did you know?
OB stars are massive, hot and relatively young stars.
6. Andromeda may have been two galaxies
Back in 2010, a team of astronomers proposed an idea that somewhere between 5 and 9 billion years ago, there was no Andromeda galaxy. They suggested that two smaller galaxies collided with one another, merging and forming what we know as the Andromeda galaxy.
Did you know?
The Andromeda galaxy got its name because it appears near the Andromeda constellation, which in turn was named for a mythical Greek princess.
7. The Milky Way is a star-maker
Our Milky Way has somewhere between 100 and 400 billion stars and contains enough material to create 100 billion more. Our spiral galaxy isn’t likely to run out of stars anytime soon. One advantage of having so many stars is that current theories suggest that most will have planets.
Did you know?
The Milky Way may have millions of planets, and many of these may have life-sustaining properties.
8. Spiral galaxies sometimes have a halo
EThe concentration of stars at the centre of a spiral galaxy's disk, known as a bulge, often has a faint halo. This halo is made of stars, lots of which are in globular clusters. These clusters are spherical star collections that orbit a galactic core.
Did you know?
The halo of the Milky Way is around 50,000 light-years in diameter.
9. The farthest spiral galaxy may be the first
As of 2012, the BX442 galaxy is not only the farthest spiral galaxy to be observed, at 10.7 billion light-years, it is also quite possibly the first spiral galaxy (that has been observed to date) to be created.
Did you know?
BX442 is known as a ‘grand design’ galaxy because its arms are clearly defined and winds significantly around its centre.
10. Large stars of spiral galaxies have a short shelf life-span
There are bright spots in spiral galaxies that can be observed, and these are large, 'new' stars. These stars do not typically last very long though, this is because they are continually burning through huge amounts of fuel.
Did you know?
When a star runs out of fuel it becomes a red giant. After this, it will either collapse into a white dwarf or begin creating helium.