Meaning of Stars
Stars form part of the solar system, and they are made up of plasma spheroids which produce heat, rays, and light. Closest to the earth is the sun.
Different types of stars
When a collection of gas collapses down from a massive molecular cloud, a protostar forms. It is the celestial body that pre-exists a T Tauri star. A protostar exists in a phase that lasts for around 100,000 years in the stellar evolution.
T Tauri star
These stars look a lot like the main sequence stars, but the pressure and temperature at their core do not suffice for the generation of nuclear fusion. This stage lasts for approximately 100 million years.
Main sequence stars
Most of the stars we have are in this category. Other than the sun, we also have Sirius and Alpha Centauri A, among others. These stars have different sizes, level of brightness, and mass. These stars have hydrostatic equilibrium. At their core, hydrogen gets converted to helium, and an enormous amount of energy is released.
Red dwarf star
They are very common, and they are a type of main sequence star. The difference is that they have low masses and are cooler. They conserve their hydrogen fuel and thus burn for longer than others.
Red giant star
Occurs when a main sequence star ages and has used up the hydrogen in its core. Fusion stops and the outward pressure is not produced. The hydrogen around the star’s core will ignite and prolong the star’s life. In turn, it will also increase in size massively.
White dwarf star
This is a star that has no hydrogen fuel and no mass that can trigger a fusion reaction of higher elements. Due to the lack of outward light pressure, it will collapse because of its gravity. They form over a period of hundreds of billions of years.
These are exotic stars that are made from neutrons. As they form, they crush protons and electrons together.
These are the largest of all stars. They use up their hydrogen fuel a lot faster. Therefore, they die young. As they die, they disintegrate.