Ever since active region 1515 (AR1515) arrived on the solar scene, it’s been crackling with flare activity. As if to upstage the Higgs boson announcement this week, AR1515 even blew its top on Monday, erupting with an M5.6 solar flare — that was just shy of the energy of the most powerful type of flare.
But at 2308 UT (7:08 EDT/4:08 PDT) on Friday, the intense active region pockmarked with a complex of sunspots showed us what it’s really made of and erupted with an X1.1 flare.
Although an X1.1 is powerful, it is still smaller than the X-class flares that occurred in March.
According to Spaceweather.com this most recent flare, which generated X-ray radiation measured by the Earth-orbiting GOES satellites, could have unleashed a storm of high-energy protons that travel along the interplanetary magnetic field (the magnetic field from the sun that interacts with our planet’s geomagnetic field). If they impact our magnetosphere, we should see an uptick in auroral activity at high latitudes.
Solar flares are caused when regions of intense magnetic activity are forced together, break — much like an elastic band snapping — and reconnect. When this occurs, solar plasma is accelerated and heated rapidly, generating intense emissions of electromagnetic radiation. Some flares, like today’s X1.1, are abundant in X-ray radiation. Although this particular flare wasn’t pointing at Earth, it is likely that sudden ionospheric disturbances (or SIDs) will have propagated through the upper atmosphere.
On Monday, the M5.6 flare caused an increase in ionization in the atmosphere over Europe causing some interruption in radio propagation.
It is not currently known if AR1515 also produced a coronal mass ejection (CME).
Image: NASA’s Solar Dynamics Observatory (SDO) spots today’s X1.1 flare through its high-definition eyes (SDO/NASA). Special thanks to @Camilla_SDO for providing the view!