The Life Cycle of a Star

By Caitlin Prescott

Stage 1: Protostar

When a star is in its first stage it is called a protostar. This stage lasts up to 10,000,000 years. This stage is where a large mass is formed out of gas in the interstellar medium. Interstellar medium, simply put is the space between stars and they mainly consist of gas and dust.

Stage 2: Main sequence

The main sequence happens once a star reaches equilibrium for the first time. Equilibrium is when the condition existing when a chemical reaction and its reverse reaction proceed at equal rates. Once this happens the star will start fusing hydrogen into helium. Fusion is the process or result of joining two or more things together to form a single entity.

Stage 3: Red Giant

The third stage is called the Red Giant, during this stage the star produces energy by the nuclear process called fusion. Red Giants are cool and bright during this stage. Stars spend a few thousand to 1 billion years in this stage until the helium in the core runs out and fusion stops.

Stage 4: The White Dwarf

The white dwarf is sadly the last stage in a stars life. It is when it starts to die. This happens because it can no longer maintain a fusion reaction. Often supernovas come from stars dying.

Origin of H, Fe, N, O

The main elements that make up a star are Helium, Oxygen, Iron, and Carbon. This is where these elements come from.

Red shift, Blue shift

Red shift and Blue shift is part of the doppler affect. It is not a change in light but that the lights wave length either becomes longer or shorter. If it is blue shifted it means there is a shorter wave length because the object is moving towards the observer. Red shifted is the opposite, Longer wave length and moving away.