Firing Off Flares
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Here’s a look at the activity on the Sun that’s gotten many talking about solar storms this week. Taken with the Solar Dynamics Observatory’s AIA 335 camera channel, which is sensitive to light emitted by Iron-14 ions in the Sun’s active corona layer, this video spans about two and a half days’ time, from February 13 to 15, 2011. Sunspot (or “active region”) 1158 is at the base of all those coronal loops you can see twisting and turning as the Sun rotates…in visible light they would appear as small dark spots on the Sun but in reality each node is easily as large as Earth!
These areas of magnetic instability have sent out several flares our way, visible here as bright flashes in SDO’s sensors. The last one, about halfway into the video, was classified as an X-category flare and was larger than any seen in the past four years. Since the Sun is just starting to enter the maximum activity period within its 11-year cycle (i.e., the Sun’s hurricane season) that makes sense, but we should expect to see more such flares over the next couple of years. Not all will be aimed at Earth, but when they are they can cause electromagnetic havoc with equipment on the ground – and in orbit – once the clouds of ejected charged particles make the 93-million-mile trip to collide with our magnetosphere.
“We’ve just witnessed the brightest flares seen for four years. This was a series of so-called X-class flares – the highest category on the solar flare ‘Richter scale’. The flares were near the center of the Sun which means associated eruptions and clouds of solar particles can travel in our direction.”
– Professor Richard Harrison, Solar physicist and Principal Investigator for STEREO
The flares shown here have already been responsible for radio and satellite outages in China. It remains to be seen if they will affect anywhere else, but one thing we can expect is increased auroral activity around the high latitudes and possibly much further south than normal. If you live in a dark area and fairly north, check the skies tonight for any pale reddish glow…it may be some low-flying northern lights! (The full “snow” moon won’t help viewing much, but you never know.)
As far as personal safety, these flares are nothing we haven’t experienced before, and are still weaker than ones we had in 2003. But it never hurts to put on some sunscreen. 🙂
Check out more info about the Sun’s activity and the recent flares on SpaceWeather.com.
Video credit: NASA/SDO and the AIA, EVE and HMI science teams.
Posted on February 17, 2011, in sun and tagged AIA, astronomy, CME, coronal loops, flare, geomagnetic, SDO, solar storm, sun, sunspot, X-class. Bookmark the permalink. Comments Off on Firing Off Flares.