FIRST SDO/AIA OBSERVATION OF SOLAR PROMINENCE FORMATION FOLLOWING AN ERUPTION: MAGNETIC DIPS AND SUSTAINED CONDENSATION AND DRAINAGE

Imaging solar coronal condensation forming prominences was difficult in the past, a situation recently changed by Hinode and the Solar Dynamics Observatory (SDO). We present the first example observed with the SDO/Atmospheric Imaging Assembly, in which material gradually cools through multiple EUV channels in a transequatorial loop system that confines an earlier eruption. Nine hours later, this leads to eventual condensation at the dips of these loops, forming a moderate-size prominence of similar to 10(14) g, to be compared to the characteristic 10(15) g mass of a coronal mass ejection (CME). The prominence mass is not static but maintained by condensation at a high estimated rate of 10(10) g s(-1) against a comparable, sustained drainage through numerous vertical downflow threads, such that 96% of the total condensation (similar to 10(15) g) is drained in approximately one day. The mass condensation and drainage rates temporally correlate with the total prominence mass. The downflow velocity has a narrow Gaussian distribution with a mean of 30 km s(-1), while the downward acceleration distribution has an exponential drop with a mean of similar to 1/6 g(circle dot), indicating a significant canceling of gravity, possibly by the Lorentz force. Our observations show that a macroscopically quiescent prominence is microscopically dynamic, involving the passage of a significant mass through it, maintained by a continual mass supply against a comparable mass drainage, which bears important implications for CME initiation mechanisms in which mass unloading is important.