Hinode XRT tracked the spunky active region, AR12831, for several days in early July.
Initially, the hot x-ray loops form straight lines connecting regions of opposite polarity. As the active region evolves, the
endpoints become twisted forming a backward S. This shape is called a sigmoid.
Sigmoidal active regions are more likely to erupt than other active regions. Therefore, understanding their formation could lead to
predicting solar flares and coronal mass ejections.
Hinode along with the Solar Dynamics Observatory (SDO) maintain a sigmoid catalog so that scientists
can easily access these events.
This XPOW was brought to you by the letter S.
Keywords: Sigmoid, AR Tracking