What is an active prominence?

An active prominence refers to an eruptive solar feature characterized by rapid changes and dynamic movements. These prominences are associated with active regions on the Sun, such as sunspots, and can be seen rising from the solar surface, often reaching heights that may extend hundreds of thousands of kilometers into the solar atmosphere. They are typically formed from dense, cooler plasma that is suspended within the hotter solar corona due to magnetic forces.

The term "active" highlights the prominence's tendency to undergo frequently dynamic behavior, such as erupting or collapsing, as opposed to stable or quiescent prominences that can last for longer periods without significant change. This is crucial in understanding solar activity because active prominences can lead to events like solar flares or coronal mass ejections, which can impact space weather and even technology on Earth.

Other options describe features that do not fit the criteria of an active prominence. For instance, stable prominences may exist but do not exhibit the rapid changes typical of active prominence behavior. Similarly, the mention of planetary features or associations with black holes does not pertain to the solar phenomena described in active prominences. Thus, the definition of an active prominence is best captured by its eruptive nature and the swift transformations it undergoes.