Answer:
Filaments and prominences
Step-by-step explanation:
Filaments are large regions of very dense, cool gas, trapped in place by magnetic fields. They usually appear long and thin above the chromosphere. This is because they are cooler than their surroundings hence they appear dark. But if they appear on the "edge" of the Sun, they appear brighter than the dark outer space behind them. In such case we call them prominences.