In the late afternoon yesterday (February 13, 2011) sunspot 1158 released a decent-sized solar flare, a magnetic eruption on the Sun. This was classified as an M6.6 flare, which is above average in explosive energy, but hardly up to the nastiness we experienced in late 2003 when the Sun was throwing an epic hissy fit.
The image here is from the Solar Dynamics Observatory, and shows the sunspot in the extreme ultraviolet part of the spectrum. This is the first solar flare sending energy toward the Earth since the Sun started its magnetic cycle up again last year. That may sound scary, but we’ll be OK. First of all, it’s not all that big a flare. Second, the effect comes in two ways: through electromagnetic energy (light), and subatomic particles. The first is already over, and the second will be buffered by the Earth’s magnetic field.
Holy cow, thanks to Emily Lakdwalla and mars_stu, here is a freaking enormous loop of plasma arcing off the surface of the Sun:
[Click to enfilamenate.]
That was taken by the Solar Dynamics Observatory at about 17:50 UT, or just an hour or so ago as I post this. Wow! That prominence must be nearly a million kilometers across![Update: Geeked on Goddard estimates it at 700,000 km.] Mind you, on the scale of this image, the entire Earth would be about 5 pixels in size.
Yegads.
OK, a few things:
1) First, there is very little danger to Earth from this event. Prominences like this tend to be local to the Sun, and collapse after a few hours. As far as I can tell, there are no flares or coronal mass ejections associated with this, which are what can hurt satellites and power grids here at home. So rest easy, and enjoy the beauty of this thing.
Wow! You can see the Sun’s rotation over the four hour interval these pictures were taken, and then the Moon flashes by. The Moon is dark because it’s between us and the Sun, so were seeing the unlit side (I have a diagram showing an approximation of the geometry of this event on my other page about it).
Moreover, scientists can use images of the sharp-edged Moon against the Sun’s disk to check on the optics of the observatory. That information can be used to sharpen the images even more. So this is fantastic, fantastically beautiful, and fantastically useful, too.
The Sun is getting back into the swing of things: a big active region on its limb erupted yesterday (October 10), sending out a small storm of subatomic particles into space. We weren’t in the line of fire, but over the next few days the rotation of the Sun will bring Active Region 11112 closer to the center of the Sun’s disk, and if that region erupts it may send a storm our way.
This shows the Sun in ultraviolet (where activity can manifest itself) from around 23:00 UT (19:00 Eastern US time) on October 11. The active region is pretty obvious there to the lower left.
A magnetogram, which shows magnetic activity, makes the region obvious as well. A recent one (shown here on the left) from around the same time as the image above again shows the active region has a lot of magnetic activity going on.
The Sun’s magnetic field lines can contain a huge amount of energy. As the gas in the Sun roils and swirls, the field lines get tangled together. If they connect, bang! They can explode, sending that energy out into space. (more…)
Our nearest star has woken up for real and for sure. After several years of stubbornsilence, the Sun has unleashed several fairly big explosions of material. Called Coronal Mass Ejections, or CMEs, these gigantic events blast out hundreds of billions of tons of matter into space. They create vast interplanetary shock waves, and when they reach the Earth can cause all sorts of havoc. They are different from solar flares, but have similar origins in the Sun’s magnetic field.
NASA’s recently-launched Solar Dynamics Observatory caught the action mid-eruption. This image shows million-degree-hot gas blasting off the surface, entangled in the Sun’s strong magnetic field. The most recent CMEs probably won’t do much more than give us pretty aurorae — they’ve already been spotted — which is good (worse effects are the loss of satellites and potential blackouts on Earth). In fact, if you live in the far north or south you may be able to see the light show.
You can read more about this at Orbiting Frog, SpaceWeather (with pictures!), Universe Today, and pretty much every other space blog on the planet. I’m probably too far south and in far too light-polluted skies to see, but give it a try if you can. Aurorae can be quite spectacular.
But if you miss it, don’t fret: I’m sure we’ll get lots of other opportunities. The Sun is gearing up for the peak of its cycle in the next three years or so, and there will be plenty of chances to watch as our sky reacts.
Last week, NASA presented the first images and videos from its latest and greatest eye on the Sun: the Solar Dynamics Observatory.
SDO has been in the works for a long, long time, and I’ve been anxiously awaiting data from it for years… so of course I was away from my computer when the images were released. Still, it was worth a few extra days to see something as back-of-the-neck-hair-raising as this:
On April 19, 2010, NASA’s newly-launched Solar Dynamics Observatory caught a massive eruption on the Sun, called a prominence, as it blasted millions of tons of 60,000 K (100,000° F) gas off the surface of the Sun. Check out this amazing footage as the material blows upward, then rains back down onto the Sun’s surface.
Holy Haleakala! If you watch carefully, you can see little hot spots flash as the gas hits the Sun again. At about 31 seconds, a thin streamer comes screaming back down; look carefully where it hits and you’ll see those spots. This animation is actually about four hours worth of images strung together. (more…)
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
"If things worked the way I wanted them to, any reporter about to do another 'sensational' story on deadly meteors would consult this volume, and bang! common sense would find its way into the news. How strange would that world be?" -- Adam Savage, Mythbusters
"Reading this book is like getting punched in the face by Carl Sagan. Frightening, but oddly exhilarating." -- Daniel H. Wilson, author of How to Survive a Robot Uprising
In the late afternoon yesterday (February 13, 2011) sunspot 1158 released a decent-sized solar flare, a magnetic eruption on the Sun. This was classified as an M6.6 flare, which is above average in explosive energy, but hardly up to the nastiness we experienced in late 2003 when the Sun was throwing an epic hissy fit.
A magnetogram, which shows magnetic activity, makes the region obvious as well. A recent one (shown here on the left) from around the same time as the image above again shows the active region has a lot of magnetic activity going on. 
