Sunspot Rotation and the M-Class Flare in Solar Active Region NOAA 11158

摘要

We measure the rotation of a sunspot in solar active region NOAA 11158 (Solar Target Identifier SOL2011-02-15) that was associated with an M-class flare. The flare occurred when the rotation rate of the sunspot reached its maximum. We also calculate the energy in the corona produced by the sunspot rotation. The energy accumulated in the corona before the flare reached , which is sufficient to meet the energy requirements for a moderately strong solar eruption. This suggests that sunspot rotation, which is often observed in solar active regions, is an effective mechanism for building up magnetic energy in the corona.