1 GK Sun

Non-thermal emission
Some fraction of electrons are accelerated to nearly the speed of light during flares and cause strong radio emission. This figure shows 1992-11-2 flare which occurred on the west limb of the Sun. The intensity became more than 1 GK (10^9 Kelvin) in contrast with the solar disk which is 10,000 K. The total radio flux became 60 times the quiet Sun during this flare.