Yesterday, an active region on the sun – basically, a collection of magnetically active sunspots – popped off a series of flares that were actually fairly energetic. NASA’s Solar Dynamics Observatory caught the action in this video:
Neat! These shots were in the ultraviolet, where flares are easier to spot.
Sunspots are where the Sun’s complex magnetic field pokes through the surface. The field lines store ridiculous amounts of energy (did you see my BAFact for today?), and allow plasma – superheated, ionized gas – to flow along them. Think of these field lines like a pillowcase full of tightly wound springs. If one of them snaps – which can happen if they get too close to each other, for example, or when the churning surface of the Sun ratchets up the tension in the field lines beyond their capacity to restrain themselves – it blasts out its energy, which then snaps other lines, which release their energy, and so on. You get a cascade of explosions, resulting in a solar flare.
Flares can be pretty small, or hugely huge. Scientists categorize them by the amount of X-ray energy released, so we have low-energy C class, medium M class, and yikesingly X class. This flare from yesterday just edged into X class territory, so it was decent, but not too bad. Happily it was on the edge of the Sun, and the blast was directed away from Earth, so it’s not expected to affect us. For further reassurance, there have been 14 previous flares since this new sunspot cycle began a couple of years ago, and we’re still here.
However, as the Sun spins, this active region is rotating toward us. If it stays active, we could see some interesting events from it that can cause aurorae on Earth. The odds of anything bad happening – power outages, or loss of satellites, for example – are low, but not entirely zero. I personally am not too worried about it, but it’s always good to keep our eyes on our nearest star. It can pack quite a punch, and we’re still a year or so away from the peak of the current sunspot cycle.
Image credit: NASA/SDO
It’s been a while since we’ve had a big flare from the Sun. Active region 1515 was looking like it might do the trick — over the past week this group of sunspots has been hissing and spitting, but the flares have been relative small. Astronomers rate flares by their X-ray energy: A, B, C, M, and X, where X is the highest. Some of the flares from AR1515 were C class and some M class – moderately strong.
Between July 5 and 6 it put out about a dozen of those smaller flares:
Then, late on July 6, it blew out the first X-class flare of the summer:
This sequence of images from the Solar Dynamics Observatory shows the flare over a bunch of different ultraviolet wavelengths, where flares are most obvious. You can see that it was pretty bright! Here’s a video showing it erupting:
The video again shows the Sun at different wavelengths of UV light. The flickering is due to the software automatically setting the brightness level; when the flare gets bright it sets the image to be dimmer, so the Sun appears to flicker. The long dashed-line spikes are not real; those are due to the way the detector in SDO sees X-ray light, like the spikes you see in bright stars in some telescopic images.
Flares occur when the Sun’s magnetic field gets tangled up. In a sense, the field short-circuits, releasing vasts of built-up energy, and we call that a flare. A big one can release 10% of the entire energy of the Sun! This can emit high-energy light and a huge blast of subatomic particles which cross the inner solar system and slam into us. While we’re safe on the ground, this can damage satellites, cause blackouts, and of course trigger gorgeous aurorae — the northern and southern lights.
This flare was still pretty small even for an X class; we had bigger ones over the past year (see the Related Posts for links to some of those). This particular group of sunspots is heading over the edge of the Sun now as our star rotates, so we probably won’t be seeing it again; sunspots tend not to last that long. But there will be more. We’re still approaching the peak of the sunspot cycle, probably late next year, so expect plenty more — and more powerful — flares to come.
Tip o’ the welder’s goggles to Camilla Corona SDO on Google+. Image credit: NASA/SDO
– HD Footage of last night’s flare
– The Sun lets out a brief flare
– The Sun aims a storm right at Earth: expect aurorae tonight!
– GORGEOUS solar eruption!
– The birth of a sunspot cluster
After I posted the video of the solar eruption earlier this week, I got a lot of questions about why material fell back from the explosion onto the Sun. The quick answer: gravity! A lot of the material from a prominence like that falls back onto the Sun because of the Sun’s strong gravity. Since the material is an ionized plasma – a gas stripped of one or more electrons — it follows the magnetic field lines of the Sun, so you can see graceful arcs of this stuff falling back down after the blast (see Related Posts below for links to more detailed descriptions of this phenomenon).
Oh, why describe it when I can show you? This video is from the NASA/JAXA Hinode spacecraft which observes X-rays from the Sun. It caught the event in loving detail:
See? Gravity does the work, but magnetism does the steering.
Tip o’ the phased plasma rifle in the 40 Watt range to Camilla Corona SDO.
– GORGEOUS solar eruption!
– Desktop Project Part 8: From filament to prominence
– The Sun decided to blow off a little steam today. Twice.
– Gorgeous flowing plasma fountain erupts from the Sun
– A fiery angel erupts from the Sun
Today, the Sun had two relatively minor — but quite cool-looking — events. One was a prominence eruption, where a loop of ionized gas is lifted from the Sun’s surface and is ejected into space, and the other an M1 class flare on the Sun’s edge. Neither will affect us here on Earth, but are interesting to watch.
The sunspot region that blew off that small flare is on the edge of the Sun rotating toward us right now, so if they continue to be active, we might see some fun flares and aurorae from them. Stay tuned!
Over at NASA’s Goddard Space Flight Center, video producer Scott Wiessinger put together a short but exquisite video of the Sun’s big flare last night — the second most powerful of this cycle, beaten out only by last year’s X6.9 event in August.
The numbers on the side are wavelengths — in this case, 171 and 131 Angstroms, way out in the ultraviolet where violent magnetic events are more easily seen.
This flare was very powerful, and blasted out a wave of particles that’s expected to hit Earth sometime tonight after midnight EST (the exact time is difficult to determine). We’ll be OK down here on Earth, but there may be sporadic communication issues, power outages (maybe), and aurorae. If you’re on Google+, Camilla Corona SDO is the person to follow. She has updates and great links!
Around midnight UTC last night, Active Region 1429 on the Sun exploded with a fairly large flare: rated at class X5.4, it was among the largest seen in the current cycle.
Video of the flare has been created using images from the Solar Dynamics Observatory:
Yowza. This flare was big enough that it may cause some communication issues and will probably lead to some nice aurorae, but otherwise is no danger to us here on Earth. I haven’t heard much else, but I’ll update this as I do.
Tip o’ the SPF 5000 to Camilla Corona SDO.
I know I’ve been writing about the Sun quite a bit lately, but I have a followup to yesterday’s cool video of the big solar flare… and you’re gonna like it.
I was fooling around with helioviewer.org, watching the flare in different wavelengths of light detected by NASA’s Solar Dynamics observatory, when I switched to 17.1 nanometers — in the far ultraviolet. At that wavelength, the glowing plasma that flows along the Sun’s magnetic field lines is very bright. The images were so beautiful, so incredible, I made a video animation of them, covering the time range of January 26, 2012 at midnight to January 28 at noon (UTC), which includes the huge X2 solar flare that erupted on the 27th. The video shows huge loops of magnetism on the Sun’s surface, glowing plasma flowing along them… and then 48 seconds in the flare changes everything. Watch:
Holy wow! Isn’t that awesome? Make sure you watch in in HD, and make it full screen to get the whole effect.
What you’re seeing is Active Region 1402, a sunspot cluster. This is a tangled collection of magnetic field lines piercing the surface of the Sun. Like a bar magnet, there are two poles to each loop, a north and a south pole. The gas on the surface of the Sun is so hot it has electrons stripped off, so it’s strongly affected by the intense magnetic field, and flows along these towering loops, which can reach heights of 300,000 km (180,000 miles) in this region.
The loops are tied to the plasma, too, and this material is twisting and roiling as it rises and sinks. The lines get tangled, and like a short circuit they can snap and reconnect. When they do, they release vast amounts of energy as a solar flare. In the video you can see the messy, disorganized loops getting more and more tangled up. Then KABLAM! The flare itself is not visible because it happened too quickly to be seen on this timescale (see the video yesterday for that). But you can see the effect on the magnetic field loops! They suddenly become far more organized, tight, and calm.
The Sun is fiendishly complex, and astonishingly beautiful. Clearly, to our brains, these things are connected. Remember, too: this beauty, this magnificence, is brought to you by science. Without our curiosity and our need to understand the Universe better, you would never have been able to watch in awe as superheated plasma arcs dwarfing the Earth itself grew and collapsed on the surface of a star one hundred fifty million kilometers away.
Think of that the next time someone says science takes away the beauty and mystery of life.
– The Sun’s still blasting out flares… BIG ones
– The Sun aims a storm right at Earth: expect aurorae tonight!
– Awesome X2-class solar flare caught by SDO
– Gorgeous flowing plasma fountain erupts from the Sun
Active Region 1402, the same sunspot cluster that blew out a solar flare and caused all the ruckus last week, is still being feisty: just before rotating to the other side of the Sun, it erupted in an intense, pulsing solar flare that actually was much more powerful than the one that happened last Monday. This was an X2 class flare, making it more than twice as energetic as Monday’s.
Happily, the flares were on the edge of the Sun’s disk, so the bulk of the radiation was aimed away from the Earth, but it still makes for some pretty dramatic footage. Using helioviewer.org I created a video showing about 2.3 hours of the Sun as seen by NASA’s Solar Dynamics Observatory. It shows the Sun in the extreme ultraviolet (at a wavelength of 19.3 nanometers if you wanna get geeky), where magnetic activity is seen easily. Watch the upper right corner of our friendly star… and make sure you make it HD and full screen.
Isn’t that awesome? The flare got so bright the automatic software dimmed the rest of the Sun to compensate, giving you an idea of just how powerful these flares can be: at peak, they can give off several percent of the entire Sun’s brightness in one small spot! I love how you can see it pulsing over the course of several minutes; I counted 10 separate flaring events. Each pulse was from a snapping of the Sun’s magnetic field lines, a cascading series created when the first one went off and triggered the rest. And each released mind-numbing amounts of energy — tens of thousands of times our entire planet’s nuclear arsenal combined. Also, you can see the arcing loop around the flare site; that’s plasma trapped in a field line. It erupts outward, but bear in mind the scale: it’s several hundred thousand kilometers across, roughly the distance from the Earth to the Moon, and it blasts away from the Sun like the devil himself is after it.
Like I said: awesome.
You might have noticed the flare looked like an elongated diamond. That’s not real! It’s a digital artifact; what’s happening is the flare got so bright it overwhelmed the pixels in the SDO detector. These collect light like a bucket collects rain. If too much light hits them, they overflow into the neighboring pixel. This flare was so bright it flooded the detector, and created that effect — technically called blooming.
We haven’t seen much of an effect from this flare — just a minor radiation storm that’s at the lowest end of the scale, nothing to worry about — since it wasn’t pointed at us. Had this been in the center of the Sun’s disk, well. That might’ve given me my chance to finally see some aurorae from Colorado. Not this time, though, and sunspots generally don’t last long enough to make it all the way around the Sun again (which takes about 30 days to spin once). But the Sun has a lot of magnetic energy still up its sleeve, and we’ll be seeing more flares like this as we approach the peak of the cycle in 2013 and 2014.
We talked about the event itself, how it was not nearly as strong as it was thought it would be (though still producing some aurorae and a bit of ground current in Sweden), what impacts it might have had, and what we can learn from things like this to protect ourselves in the future.
I really enjoyed this interview; Patt is knowledgeable and easy to talk to, and I hope I can be on the show in the future to talk about more astronomical events!
The solar storm that erupted from the Sun yesterday reached the Earth today at about 15:00 UTC (10:00 a.m. Eastern US time). The wave of subatomic particles has been impacting the Earth’s magnetic field, and we’re starting to see some auroral activity:
Isn’t that lovely? That was taken at 18:00 UTC today from a webcam in Abisko, Sweden. Can you see the handle of the Big Dipper right below the green curtain? [More aurora webcam sites are listed below.]
The two biggest questions I’m getting on Twitter and Google+ are 1) is there any danger to this storm, and b) can I see the aurora from [my location]?
First, no, we’re not in any danger from this event. Even though it sounds terrifying — an explosion the equivalent of billions of nuclear weapons launching hundreds of millions of tons of subatomic particles Earthward at speeds of million of kilometers per hour! — we’re pretty well protected down here on the surface. The Earth’s magnetic field catches the particles, and most of those get dumped harmlessly in our upper atmosphere. That can create the aurora displays, but won’t dose everyone with radiation and give them superpowers.
Sorry. [UPDATE (19:00 UTC): a ground current surge was reported in Sweden, but so far that’s the only physical impact I’ve heard of.]
But the aurorae are pretty cool, and that brings us to the second question. The answer depends on where you are, and when it’s dark out. As I write this, activity is on the rise. Here are some live webcams for aurorae, some of which are showing spectacular activity! Note they only show views when it’s nighttime locally:
As for seeing them wherever you are, that’s tough to say. The Geophysical Institute has a map showing predicted activity for North America, for example, and NOAA’s Space Weather Prediction Center has a continuously updated map showing auroral activity for both hemispheres. Universe Today has a guide on how to see the aurorae, and Astronomy magazine has a discussion of aurorae, too.
I’m getting conflicting info on potential aurorae tonight; the webcams in Scandinavia listed above are showing strong (and gorgeous) activity, but the prediction for Canada and the US appear moderate at best. But don’t let that discourage you! If you have clear skies, go outside once it’s good and dark and take a look. Even if there’s no aurora, you can see Venus and the thin crescent Moon to the west right after sunset, and that’s always a plus. And if things perk up, you might get a nice light show to the north, too!