The Sun's Structure
The Sun's structure consists of several layers: the core, where nuclear fusion generates energy; the radiative zone, where energy moves outward by radiation; the convective zone, where energy is transported by convection currents; the photosphere, the visible surface; the chromosphere, a thin, reddish layer above the photosphere; and the corona, the Sun’s outermost, hot, and diffuse atmosphere. As the central star, the Sun’s energy sustains the entire solar system.
The Sun's Structure
The Sun's structure consists of several layers: the core, where nuclear fusion generates energy; the radiative zone, where energy moves outward by radiation; the convective zone, where energy is transported by convection currents; the photosphere, the visible surface; the chromosphere, a thin, reddish layer above the photosphere; and the corona, the Sun’s outermost, hot, and diffuse atmosphere. As the central star, the Sun’s energy sustains the entire solar system.
💡 Key Takeaways
- Identify the Sun's key layers: core, radiative zone, convective zone, and the outer atmosphere (photosphere, chromosphere, corona).
- Understand how the Sun generates energy in the core via nuclear fusion.
- Describe how energy moves outward from the core through radiative and convective transport to the surface.
- Differentiate the photosphere as the visible surface from the chromosphere and corona as the outer atmosphere, and note the solar wind.
❓ Frequently Asked Questions
What is the Sun's core and what process happens there?
The core is the Sun's hottest region (~15 million K) where hydrogen nuclei fuse through the proton–proton chain, generating energy.
What is the radiative zone and how is energy transported there?
In the radiative zone, energy moves outward mainly by photons; photons are absorbed and re‑emitted many times, taking a long time to reach the outer layers.
What is the convective zone and how is energy transported there?
In the convective zone, hot plasma rises and cooler plasma sinks, transporting energy by convection and creating surface granulation.
What is the Sun's photosphere?
The photosphere is the visible 'surface' of the Sun from which most light escapes; it’s where sunspots appear and the solar spectrum is formed.