Sun’s Radiative zone

Below about 0.7 solar radii, solar material is hot and dense enough that thermal radiation is the primary means of energy transfer from the core. This zone is not regulated by thermal convection; however the temperature drops from approximately 7 to 2 million kelvin with increasing distance from the core.

The Sun’s Core

99% of the power is generated within 24% of the Sun's radius

The core of the Sun is considered to extend from the center to about 20–25% of the solar radius. It has a density of up to 150 g/cm3 (about 150 times the density of water) and a temperature of close to 15.7 million kelvin (K). By contrast, the Sun's surface temperature is approximately 5,800 K. Recent analysis of SOHO mission data favors a faster rotation rate in the core than in the rest of the radiative zone Through most of the Sun's life, energy is produced by nuclear fusion through a series of steps called the p–p (proton–proton) chain; this process converts hydrogen into helium.

Our Sun

The Sun is the star at the center of the Solar System

Sun Flare

The Sun is the star at the center of the Solar System. It is almost spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,684 km (865,374 mi), around 109 times that of Earth, and its mass (1.989×1030 kilograms, approximately 330,000 times the mass of Earth) accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen, whereas the rest is mostly helium. The remaining 1.69% (equal to 5,600 times the mass of Earth) consists of heavier elements, including oxygen, carbon, neon and iron, among others.