14 Nature their analysis of Yohkoh images of 47 loops of coronal gas sculpted by the arching magnetic fields.
In their study, Klimchuk and Porter deduced from Yohkoh images that a coronal gas loop gains heat at a rate inversely proportional to the square of the loop's length.
The high thermal conductivity of the hot coronal gas
, solar astronomers have believed, meant that energy deposited anywhere along a coronal loop quickly spreads along its entire length, obscuring its point of origin.
To create prominences, coronal gas
must somehow cool to less than one-hundredth of its original temperature.
This holds that when the Sun is nearly spotless its magnetic field resembles a simple dipole magnet augmented by field lines near the magnetic equator that stretch outward, dragging the coronal gas