Composition of the Sun

The Sun is a massive ball of gas, primarily made of hydrogen and helium, driving nuclear fusion at its core. Understanding its composition helps us grasp how it generates energy and influences the solar system, including space weather and stellar evolution.

1. Hydrogen

   • Comprises about 74% of the Sun's mass.
   • The primary fuel for nuclear fusion processes in the Sun's core.
   • Essential for the formation of helium and heavier elements through fusion reactions.

2. Helium

   • Accounts for approximately 24% of the Sun's mass.
   • Produced as a byproduct of hydrogen fusion in the core.
   • Plays a crucial role in the Sun's energy output and stability.

3. Metals (heavier elements)

   • Refers to all elements heavier than helium, including carbon, oxygen, and iron.
   • Comprise about 2% of the Sun's mass, but are vital for various processes.
   • Contribute to the Sun's chemical composition and influence stellar evolution.

4. Plasma state

   • The Sun is primarily composed of plasma, a state of matter where electrons are stripped from atoms.
   • Allows for the conduction of electricity and the generation of magnetic fields.
   • Essential for the Sun's dynamic behavior, including solar flares and sunspots.

5. Core

   • The innermost layer where nuclear fusion occurs, generating energy.
   • Extremely hot, with temperatures reaching around 15 million degrees Celsius.
   • The source of the Sun's luminosity and heat, driving all solar processes.

6. Radiative zone

   • Surrounds the core and extends outward to about 70% of the Sun's radius.
   • Energy produced in the core is transferred outward through radiation.
   • Can take millions of years for energy to move through this zone due to dense matter.

7. Convection zone

   • The outer layer of the Sun's interior, where energy is transported by convection currents.
   • Cooler plasma sinks while hotter plasma rises, creating a cycle.
   • Responsible for the Sun's surface granulation and contributes to solar activity.

8. Photosphere

   • The visible surface of the Sun, where light is emitted.
   • Temperature is around 5,500 degrees Celsius, giving it a yellowish appearance.
   • Features sunspots, which are cooler areas caused by magnetic activity.

9. Chromosphere

   • A thin layer above the photosphere, visible during solar eclipses.
   • Temperature increases with altitude, reaching up to 20,000 degrees Celsius.
   • Contains spicules, which are jets of gas that erupt from the Sun's surface.

10. Corona

    • The outermost layer of the Sun's atmosphere, extending millions of kilometers into space.
    • Extremely hot, with temperatures exceeding 1 million degrees Celsius.
    • Visible during a total solar eclipse and is the source of solar wind, affecting space weather.