Double eruption reported on solar surface- geomagnetic storm alert

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. Yesterday’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, possibly causing geomagnetic storms when it arrives. High-latitude sky watchers should be alert for auroras.

Space Weather