Synopsis of the Nugget

This particular nugget presents really exciting new science, but it does so at a high level. This page offers a simple view of the discoveries it reports.

We basically have two items of compelling interest. First, it's well-known that CMEs (Coronal Mass Ejections) correlate with long-duration solar flares. This is important because CMEs play the biggest role in "space weather", i.e. solar disturbances out in our human part of the solar system. We would like to use those long-duration flares as a guide to the occurrence of a CME. These events from November, 2000, stand this correlation on its ear. Here we had a whole sequence of quite impulsive flares with strong and precise CME correlations. After reading this nugget, nobody could sensibly ever claim again that flares and CMEs are physically distinct.

Second, these events were "homologous", meaning that they looked quite similar to one another. This is difficult to comprehend, because a CME re-structures the coronal magnetic field in an irreversible manner, so that an exactly homologous event could not happen theoretically. This nugget shows clear evidence for newly emerging magnetic flux that feeds the successive restructurings. "Emerging flux" means magnetism boiling up through the photosphere from deep inside the Sun.

The discovery? The data strongly suggest that the emerging flux has a coherent pattern extending over the three days of homologous flaring. This pattern apparently persists in such detail that extraordinarily similar flares and CMEs can occur repeatedly, with the new magnetism re-creating the coronal structures as fast as necessary. This is perhaps the best-observed example of this kind of coherence and (in my opinion) is a big deal because of its implications for the organization of magnetism beneath the surface of the Sun.


Hugh Hudson <hudson@isass1.solar.isas.ac.jp>.