Our source of light, a vast sphere of luminous gas, Sun is the only star in our solar system. The Sun is 3,32,945 times more massive than Earth, and 750 times more massive than all of the planets in the Solar system put together.
Its light is a by-product of gas-fuelled nuclear reactions in its core. It’s gravity pulls gas inwards, but the pressure of the gas at the centre pushes outwards. The two forces balance to give the Sun its ball shape.
The Sun’s Surface
Photosphere: Sun’s visible surface looks bumpy here due to hot gas rising up from inside the star.
Faculae: The hottest areas called Faculae, look almost white and are highly active regions created by Sun’s magnetic field.
Flares: These are massive bursts of energy that explode in Sun’s lower atmosphere.
Spicules: Short-lived jets of gas shoot out from the surface.
Prominences: Sometimes giant clouds of gas loop out hundreds of thousands of kilometres.
Six Layers of The Sun
- Corona: The outer atmosphere, seen during an eclipse.
- Chromosphere: The inner atmosphere.
- Photosphere: The visible surface of the Sun from which energy is released in a blaze of light.
- Convective Zone: The layer through which Sun’s energy travels outwards through the Sun by “convection”.
- Radiative Zone: The layer through which energy travels outwards from the core as radiation.
- Core: The center of Sun where nuclear reactions convert Hydrogen to Helium, producing energy.
Material streams from the corona (outer layer) are known as the solar wind. Solar winds travel towards Earth at about 450km/sec (280 miles/sec). The wind causes gas particles above Earth’s polar regions to glow and give colorful light displays called Auroras.
It shines steadily now, but in about the upcoming 5 billion years, it will swell up before dying as a cold, dark cinder in space.
The Sun is about 5 billion years old. It is about 1.4 million Km (870,000 miles) across.