A solar prominence is a large, bright, loop-like structure of ionized gas (plasma) that extends outward from the Sun’s surface, anchored in the photosphere and reaching into the Sun’s outer atmosphere called the corona
. It consists mainly of cooler, denser plasma compared to the surrounding hot corona, composed primarily of electrically charged hydrogen and helium
. Prominences form along tangled and twisted magnetic field lines generated by the Sun’s internal dynamo, which support the plasma against gravity
. They can last from a few hours to several months and may stretch hundreds of thousands of kilometers, sometimes reaching lengths comparable to the radius of the Sun
. When viewed against the dark background of space, they appear bright, but when seen against the Sun's bright disk, they appear as dark filaments
. There are different types of prominences based on their magnetic environment and activity:
- Active region prominences form in strong magnetic fields near sunspots and erupt more frequently, lasting hours to days.
- Quiescent prominences form in weaker magnetic fields away from active regions, are more stable, and can last weeks to months
If a prominence becomes unstable and erupts, it can release plasma into space as a coronal mass ejection (CME)
. In summary, a solar prominence is a large, cool, bright arch of ionized gas suspended by magnetic fields above the Sun’s surface, often visible during solar eclipses or with specialized instruments
