Space Weather: Stongest X-Flare of the year results in very bright Auroras

Long-lived sunspot AR1967 returned to the Earthside of the sun on Feb. 25th and promptly erupted, producing an X4.9-class solar flare.  This is the strongest flare of the year so far and one of the strongest of the current solar cycle.

Coronagraphs onboard the Solar and Heliospheric Observatory tracked this material as it raced away from the sun, eventually forming a bright CME, pictured below.. Radio emissions from shock waves at the leading edge of the CME suggest an expansion velocity near 2000 km/s or 4.4 million mph. If such a fast-moving cloud did strike Earth, the resulting geomagnetic storms could be severe. However, because its trajectory is so far off the sun-Earth line, the CME will deliver a no more than a glancing blow.

A G1-class geomagnetic storm is in progress following the glancing impact of a CME on Feb. 27th at 1645 UT. Sky watchers in Europe are reporting bright auroras. Ruslans Merzlakovs sends this picture from Nykøbing Mors, Denmark:

"A very bright aurora splashed in the afternoon sky at 9 P.M. Danish time," says Merzlakovs. "This picture is a 30 second exposure at ISO 1600."NOAA forecasters expect CME effects to last for as much as 24 hours.

- SpaceWeather.com