Possible X-Class Flare for the 4th

4TH OF JULY FIREWORKS: Chances of an X-flare today are increasing as sunspot AR1515 develops a ‘beta-gamma-delta’ magnetic field that harbors energy for the most powerful explosions. The sunspot’s magnetic canopy is crackling with almost-X class flares, the strongest so far being an M5-flare at 09:54 UT. Each “crackle” releases more energy than a billion atomic bombs, so these are 4th of July fireworks indeed.

The sunspot itself is huge, stretching more than 100,000 km (8 Earth-diameters) from end to end. This movie from NASA’s Solar Dynamics Observatory shows the behemoth growing and turning toward Earth over the past five days:

Another picture that dramatically illustrates the size of AR1515 is this 4th of July sunrise shot from Stefano De Rosa of Turin, Italy.

If any major eruptions do occur today, they will certainly be Earth-directed. The sunspot is directly facing our planet, so it is in position to cause radio blackouts, sudden ionospheric disturbances, and geomagnetic storms.




INCOMING CME? A magnetic filament in the sun’s northern hemisphere erupted on Jan. 5th and hurled a CME in the general direction of Earth. At first it appeared that the cloud would sail north of Earth and completely miss our planet. Subsequent work by analysts at the Goddard Space Weather Lab suggests a different outcome: the CME might deliver a glancing blow to Earth’s magnetic field on Jan. 7th. Click to view an animated forecast track:

NOAA forecasters were already calling for a 40% chance of polar geomagnetic storms on Jan. 7-8 in response to a high-speed solar wind stream. The arrival of a CME would boost the chances even more.

10/01 Double Sunspot Eruption

DOUBLE ERUPTION: On October 1st around 10:17 UT, widely-spaced sunspots 1302 and 1305 erupted in quick succession, revealing a long-distance entanglement which was not obvious before. NASA’s Solar Dynamics Observatory (SDO) recorded the double blast:

Since it was launched in 2010, SDO has observed many “entangled eruptions.” Active regions far apart but linked by magnetic fields can explode one after another, with disturbances spreading around the stellar surface domino-style. Saturday’s eruption appears to be the latest example.

The part of the eruption centered on sunspot 1305 hurled a coronal mass ejection toward Earth. The relatively slow-moving (500 km/s) cloud is expected to reach our planet on Oct. 4th or 5th, possibly causing geomagnetic storms when it arrives. High-latitude sky watchers should be alert for auroras.