What are the whirling fountains of hot gases on the Sun's surface called?

The whirling fountains of hot gases on the Sun's surface are known as prominences. These are large, bright features that extend outward from the Sun's surface, often in looped arcs, and are composed of plasma. They can erupt and spread across the solar atmosphere, showcasing the Sun's dynamic and active nature.

Prominences typically occur in areas of strong magnetic fields and are visible during solar eclipses as bright, glowing structures surrounding the Sun's edges. They can last for days or even weeks before dissipating, and they play a crucial role in the transfer of energy and material from the solar interior to the outer atmosphere, contributing to various solar phenomena.

This understanding of solar prominence underscores its importance in the context of solar activity and its impact on space weather, which can affect satellite communications and power grids on Earth.