A long-lived solar prominence that lasts up to several months, changing little in appearance. Quiescent prominences are arch-shaped, several hundred thousand kilometres long, a few thousand kilometres thick, and up to 50 000 km high. When seen against the solar disk they appear as darker features called filaments. Quiescent prominences are found to the poleward side of active regions. Over the course of the 11-year sunspot cycle they gradually migrate to higher latitudes, eventually forming a polar crown at sunspot minimum. Quiescent prominences are most frequent on the rising portion of the sunspot cycle.