At 03:48 UT on August 9 (earlier today as I write this), the Sun blasted out another flare, the largest of the cycle so far. It was seen by the orbiting Solar Dynamics Observatory:
[Click to ensolarnate.]
This image shows the Sun in the far ultraviolet; sunspots appear bright at this wavelength and the flare is pretty obvious! It came from a sunspot that is near the Sun’s limb. Since it was so far to the side it’s unlikely to do us much harm here on the Earth’s surface, though there may be some satellite communication issues. It also blew out a storm of subatomic particles, which might potentially harm astronauts in space. I haven’t heard yet if the crew on the space station will need to seek shelter deeper inside the structure (they’ve had to do that before in solar events, but there’s never been any case of diagnosed harm).
This was an X6.9 flare, which is pretty big, but still not like the ones we saw in late 2003 which were far more powerful. Still, this is the biggest flare from the new solar cycle, and I think the first flare from this particular sunspot, named Active Region 1263. Last week, AR 126a blew out several flares, but none as big as this one.
By coincidence I was at Big Bear Solar Observatory in California just two days ago, and saw AR 1263 roiling on the Sun’s surface. 1261 was already about to slip behind to the far side of the Sun, and I didn’t think much of 1263 because it was near the edge as well. It goes to show you that with our nearest star, it’s best to expect the unexpected!
… and the astronomers with whom I talked were keeping their eyes on several other spots on the Sun as well. The new solar cycle is ramping up, so one thing I can say with some certainty is that we’ll see more and more powerful flares as time goes on.
[Updated to add: I originally wrote that this was an M6.9 flare, when it is in fact an X6.9 flare, which is ten times more powerful, and the biggest so far in years. To avoid confusion, I simply corrected the mistake in the post. My apologies.]