Structure:
1. Core: Central region where nuclear reactions take place, with temperatures around 15 million°C (27 million°F).
2. Radiative Zone: Layer outside the core where energy generated by nuclear reactions is transferred through radiation.
3. Convective Zone: Outer layer where energy is transferred through convection, with plasma rising to the surface and cooling.
4. Photosphere: Visible surface of the Sun, with temperatures around 5,500°C (10,000°F).
5. Chromosphere: Layer above the photosphere, visible during solar eclipses, with temperatures around 10,000°C (18,000°F).
6. Corona: Outer atmosphere of the Sun, visible during solar eclipses, with temperatures around 1-2 million°C (1.8-3.6 million°F).
Characteristics:
1. Mass: Approximately 330,000 times the mass of Earth.
2. Radius: Approximately 109 times the radius of Earth.
3. Surface Temperature: Around 5,500°C (10,000°F).
4. Luminosity: Emits around 3.8 x 10^26 watts of energy per second.
5. Composition: Primarily hydrogen (75%) and helium (25%).
Life Cycle:
1. Protostar: Formation of the Sun from a collapsing molecular cloud.
2. Main Sequence: Current stage, fusing hydrogen into helium in the core (around 5 billion years so far).
3. Red Giant: Expansion of the Sun in around 5 billion years, engulfing inner planets.
4. Helium Flash: Brief helium fusion period.
5. White Dwarf: Final stage, a small, hot, and extremely dense star.
6. Black Dwarf: Theoretical final stage, a cold and dark star (not yet observed).
