Lifecycle of a Star

This lesson covers the lifecycle of a star — from its birth in a nebula to its final fate as a white dwarf, neutron star or black hole — as required by the Edexcel GCSE Combined Science specification (1SC0). Understanding stellar evolution is essential for the astronomy section of the physics paper.

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Overview: Two Pathways

The lifecycle of a star depends on its mass. Stars roughly the mass of our Sun follow one pathway; stars much more massive than the Sun follow another.

graph TD
    A["Nebula"] --> B["Protostar"]
    B --> C["Main Sequence Star"]
    C -->|"Sun-sized star"| D["Red Giant"]
    C -->|"Massive star"| E["Red Supergiant"]
    D --> F["Planetary Nebula"]
    F --> G["White Dwarf"]
    E --> H["Supernova"]
    H --> I["Neutron Star"]
    H --> J["Black Hole"]

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Stage 1: Nebula

A nebula is a large cloud of dust and gas (mainly hydrogen) in space. Gravity causes denser regions of the nebula to collapse inward.

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Stage 2: Protostar