EVERYTHING ABOUT ALL TYPES OF STARS
Although we all learn about stars when we are in primary school and perhaps even high school, not many of us actually know the various types of stars that are present in our solar system.
Unlike other aspects of the universe, stars are quite versatile. They are more than just rocks – in fact, they aren’t rocks at all, to many people’s surprise! Not only this, but stars are also made of different colors and brightness, for example. So, throughout this article, we will be taking a look at different kinds of stars, namely the various stellar classifications, stars’ life cycles, and more.
Seven Spectral Types of Stars
First things first: there are different spectral types of stars. These are called O (they are blue), B (blue), A (blue), F (blue/white), G (white/yellow), K (orange/red), and M (red).
- O-type stars tend to have a longevity of 10 million years. Their radius is also around ten times the size of the sun’s, and they are around fifty times bigger than the sun in terms of their mass. They are, however, the rarest kind.
- B-type stars are much smaller in mass, but “live” around 100 million years.
- A-type stars are smaller too and survive for around 100 million years.
- F-types survive for 3000 million years.
- G-types live for 10 000 million years.
- K-types "die" after 50 000 million years.
- M-types stay around for about 200 000 million years. M-types are also some of the most common, making up around 80% of all stars in our solar system.
This system of classification is called the Morgan Keenan system. Find out everything about it here.
These kinds of stars are about as big as the sun. They have hydrogen in their core and they seem yellow in color. The brightest one of these in our universe is called Alpha Centauri and it is very close to the Earth. It is a part of a binary, which is a system or two stars orbiting around the same center.
Hot Blue Stars
These stars are very large in mass, but they therefore also last a much longer time than other smaller stars. For example, they can live and then die within only a few million years (they are usually the O type). These stars turn into a bright blue because of the heat they emit. They are also some of the brightest kinds of stars, so we can usually see many of them from Earth.
Red Dwarf Stars
As you saw from the previous classification, the smaller the star, the longer it lives. This is the case for red dwarf stars, as you may have gathered from the name. Red dwarf stars are the most common in our galaxy but they are also very small and thus difficult to see. We cannot see them without a telescope.
Red Giant Stars
This star is in the Lyra constellation, and it is the constellation’s brightest star. It is around 25.5 light years away from the Earth. We can only see it from the Northern Hemisphere. It used to be the North Pole star around 12, 000 B.C.E., and it’s expected to regain this status around the year of 13,727. Sadly, most of us won’t get to see that happening!
These stars emerge from stars that were previously large (such as the size of the sun) that have burned all the material they have (hydrogen, helium, and the heavier elements found at their core). Then, they become like a giant crystal and they are very hard to see. Sometimes, you can see it in the winter, but it is rather rare.
There are also supergiant stars, which is when stars run out of hydrogen and burn helium, as well as neutron stars that are the collapsed cores of stars that are massive in size.
Binary stars, as you may remember, are stars which revolve around the same barycenter. These systems rotate around a specific mass, and it’s one of the most common kinds of stars that we can see in the sky. In fact, almost half of the stars in the system are binary stars. You also have double stars which are stars that seem to be very close to one another, but aren’t really next to each other.
They may seem like they are binary because they are in the same line-of-sight when we look at them from Earth, but they aren’t binary because they don’t rotate around each other. There is also the eclipsing binary, which is when two close stars who seem to only make up a single star are actually a binary of two stars which have different levels of brightness. So it looks like one is eclipsing the other!
There is also the X-Ray binary star, which is when one of the stars is a different kind – a white dwarf, a neutron star, or even a black whole. This creates X-rays because the matter is taken away from the normal star, meaning that it then falls into the star which has collapsed.
Finally, there are a few other kinds of stars, including the Cepheid variable star, which is a kind of star that pulsates in size on a regular basis. They also change in brightness. For example, when it is bigger, it is also dimmer, but the opposite is also true.
And yet, the stars we see are, in fact, not a solid thing whatsoever. They are made up of various gasses that, when put together, emit so much energy that they can shine extremely bright and be seen hundreds of light-years away from the Earth. This is similar to love: we see couples that are made up of two people who alone do not shine as bright, and yet, when they unite, they brighten up the entire room. When they unite, however, they can outshine the rest of us. They fit so well together and emit so much energy that we can all feel it when in the same room.