Stars and their Life cycle
Stars are the bright objects that are seen when looking up at the night sky. These do not have a solid surface as they are made up of mostly hydrogen. The temperatures of a star can range from 30 000°C to 300 000°C. The colour of the star depends on the temperature.
Stars go through different stages in their lives. They begin forming from clouds and dust. These are called Stellar Nebula. The force of gravity is what then makes the dust particles join. As they join, gravitational energy is converted into heat energy and the temperature rises. Once the temperature is high enough, it then undergoes nuclear fusion to form helium nuclei and gives out massive amounts of heat and light. A star is then born. This stage is called the Main Sequence star and lasts about 10 billion years. Eventually the hydrogen begins to run out and the star turns into a Red Giant and the surface cools. A sun like star ours which is smaller. This then cools and contracts and turns into a White Dwarf. The White Dwarf’s light fades completely and it becomes a Black Dwarf. However, bigger stars glow brightly again and undergo more fusion and eventually explode into a Supernova.
Stars go through different stages in their lives. They begin forming from clouds and dust. These are called Stellar Nebula. The force of gravity is what then makes the dust particles join. As they join, gravitational energy is converted into heat energy and the temperature rises. Once the temperature is high enough, it then undergoes nuclear fusion to form helium nuclei and gives out massive amounts of heat and light. A star is then born. This stage is called the Main Sequence star and lasts about 10 billion years. Eventually the hydrogen begins to run out and the star turns into a Red Giant and the surface cools. A sun like star ours which is smaller. This then cools and contracts and turns into a White Dwarf. The White Dwarf’s light fades completely and it becomes a Black Dwarf. However, bigger stars glow brightly again and undergo more fusion and eventually explode into a Supernova.
A Supernova
A supernova occurs when collapsing super giants explode. They are extremely luminous and cause a huge burst of radiation. The burst of radiation they produce can outshine an entire galaxy. This burst of radiation fades from our view after several weeks or months. During this short period of time, a supernova can radiate as much energy as the sun over its lifetime. A supernova also provides all the heavy elements that are in the universe. On average, every 50 years, a supernova will occur.
The exploding Supernova throws the outer layers of dust and gas into space, leaving a very dense core. This is called a Neutron star. If the star is big enough it will become a Black Hole. The dust and gas from the Supernova will form into a second generation stars like our sun.
The exploding Supernova throws the outer layers of dust and gas into space, leaving a very dense core. This is called a Neutron star. If the star is big enough it will become a Black Hole. The dust and gas from the Supernova will form into a second generation stars like our sun.