A Star's Lifecycle
Like all things, stars go through cycles in their life. They start off small then gradually become larger as they age. The diagram below displays the cycle of a star's life.
Nebula
A nebula is the very beginning of a star's life. A nebula is a gigantic cloud of dust and gas. The word 'Nebula' in Latin means 'cloud'. Nebulae are mainly made up of hydrogen and helium gases. They are found in not one but many shapes and sizes, a common shape of a nebula looks much like a Horsehead as well as one that looks like a crab. Astronomers believe that nebulae are made from huge collapse of gas. There are many types of Nebula here are a few examples: Emission Nebula, Reflection Nebula and Planetary Nebula.
Planetary Nebula- Despite its name, planetary nebulae has nothing to do with planets. A planetary nebula is a nebula formed from by a shell of gas. In most cases, the gas guarding the nebula was released from another extremely hot star, such as a red giant or supergiant star. As the giant star explodes, the core of the star is exposed.
Emission Nebula- An emission nebula emits light energy. They are formed when ultraviolet light from a very hot star comes into contact with a cloud of hydrogen gas; (the UV radiation reduces the electrons from the hydrogen atoms). The free electrons combine with protons, forming hydrogen and red light.
Reflection Nebula- A reflection nebula is a nebula that glows as the dust in it reflects the light of nearby stars. These nebulae are often a bluish colour because blue light is more efficiently reflected, rather than red .
Planetary Nebula- Despite its name, planetary nebulae has nothing to do with planets. A planetary nebula is a nebula formed from by a shell of gas. In most cases, the gas guarding the nebula was released from another extremely hot star, such as a red giant or supergiant star. As the giant star explodes, the core of the star is exposed.
Emission Nebula- An emission nebula emits light energy. They are formed when ultraviolet light from a very hot star comes into contact with a cloud of hydrogen gas; (the UV radiation reduces the electrons from the hydrogen atoms). The free electrons combine with protons, forming hydrogen and red light.
Reflection Nebula- A reflection nebula is a nebula that glows as the dust in it reflects the light of nearby stars. These nebulae are often a bluish colour because blue light is more efficiently reflected, rather than red .