What are stars?

Stars are enormous balls of plasma held together by their own gravity and fuelled by nuclear fusion. They come in a variety of sizes and colors, from white dwarfs to red giants.

Stars form when clouds of gas and dust collapse due to their own gravity. As the gas and dust collapses, it heats up and forms a protostar. The protostar continues to heat up as more gas and dust collapses and eventually becomes hot enough to begin nuclear fusion. This is what makes stars shine with their characteristic light.

The Different Types of Stars

There are several different types of stars, depending on their mass and temperature. The most common type of star is a Main Sequence star, such as our Sun. These are stars that are in the middle of their lifecycles and have a temperature between 11,000 to 60,000 Kelvin.

Red giants are stars that have a temperature below 11,000 Kelvin and they have exhausted their fuel supply. White dwarfs are stars that have exhausted their fuel supply and have a temperature above 60,000 Kelvin.

Neutron stars are the remains of an exploded star and are the densest stars in the universe. They contain more mass than the sun, yet are the size of a city. Black holes are the remains of a collapsed star and are areas of space-time where gravity is so strong that not even light can escape.

The Lives of Stars

Stars are born and eventually die, usually like a dramatic finale. Large stars will end their lives in a supernova, where their outer layers are blasted away and their remaining core can become a neutron star or black hole. Small stars, like the Sun, will expand and become a red giant and eventually cool off and dim to become a white dwarf.

Conclusion

Stars are immensely massive gravitationally bound balls of hot plasma, fueled by nuclear fusion. They come in several varieties and sizes and have a unique life cycle that ultimately leads to their demise. They are the main source of light and warmth in our universe and an integral part of the celestial landscape.