The visible surface of the Sun (the photosphere) is around 6,000°C. But a few thousand kilometers above it – a small distance when we consider the size of the Sun – the solar atmosphere (the corona) is hundreds of times hotter, reaching a million degrees Celsius or higher.
The reason why has been puzzling scientists for decades, having finally been confirmed experimentally for the first time: Alfvén waves, first proposed in 1942, for which the Swedish scientist Hannes Alfvén won the Noble prize in 1970.
Alfvén waves are magnetic waves of plasma which bypass the photosphere before exploding with heat in the Sun’s upper atmosphere.
These waves appear when bulk motions of electrically charged particles disturb the magnetic field found on the surface of the Sun (fields which are visible as dark sunspots).
The heat waves travel along what are known as solar magnetic flux tubes before bursting into the corona, creating its enormous temperature.
MORE LIKE THIS
❤️ Brainstash Inc.