Sun

• Sun


  The center of the solar system and the largest object in it holding 99.8% of the total mass
• Sun

  • Giant ball of hot gas (73.4% hydrogen and 25% helium)
  • Yellow dwarf star that is 4.5 billion years old
  • Diameter of 1.39 km
• Sun's rotation

  Counterclockwise direction (differential; 25 days in its equator and closer to 35 days near the poles)
• Sun

  • Its gravity holds everything in our solar system in an orbit around it from the biggest planets to the smallest dust particles
• Sun

  Produces a tremendous amount of energy that travels to Earth as light and heat, essential for life
• Core

  Centermost region of the Sun where hydrogen turns into helium through nuclear fusion that releases tremendous energy in the form of light and heat
• Core

  • Temperatures are believed to reach more than 15 million degrees Celcius (being considered as the hottest region of the Sun)
  • Density (150 g/cm^3) and temperature decreases as we move to the outward layers
• Radiative Zone

  • In between the core and the convection zone
  • Energy in this layer transports outward through radiative diffusion and thermal conduction (radiant heat) which travels in the form of electromagnetic radiation by photons (takes millions of years to travel through this zone)
  • Transfers energy by bouncing from particle to particle
• Radiative Zone

  • Density reduces at its edge from 20 g/cm^3 to 0.2 g/cm^3
• Convection Zone

  • Outermost layer of the Sun's interior
  • Plasma is cooler and less dense than in the radiative zone
  • Uses convection mode/currents to transfer energy
• Convection Zone


  • Temperature at its base is about 2 million degrees Celcius which is low enough for heavier ions like carbon, oxygen, nitrogen, iron, and calcium to hold on to some of their electrons
• Photosphere

  • Has a thickness of about 500 km and all visible light from the Sun comes from this layer (the layer we see when we look at the Sun)
  • Made up of hot glowing gas
• Photosphere

  • The coolest part of the Sun with a temperature coming down to approximately 5500 degrees Celcius and with an increase in height, the temperature drops
  • Where the phenomenon of Sunspots happen
• Chromosphere


  • A dim red ring (of reddish pink gas) and a thin layer that lies just above the Photosphere
  • Visible light can only be seen during Solar Eclipses when the Photosphere is hidden
• Chromosphere

  • An increase in height causes its temperature to increase
• Corona


  • Outermost layer of the Sun's atmosphere that lies above the Chromosphere
  • Hotter than the Photosphere and extends millions of kilometers into space
  • Can be seen as a faint white glowing halo during total Solar Eclipses
• Corona

  • Its temperature spreads up to 2 million degrees Celcius
  • Coronal mass ejection, solar winds, and solar flares are phenomenons related to Corona