Tag: prominence

Purple shag Sun

By Phil Plait | November 1, 2012 10:05 am

The great astrophotographer Andre van der Hoeven sent me a shot he took of the Sun a few days ago. Looks like either Barney or the Grape Nehi folks paid it a visit:

[Click to envioletenate.]

Pretty cool. First, of course, the purple color is not real. It’s just the color Andre chose for this picture when he processed it. Second, he used an Hα filter, which lets through a very narrow slice of light (actually in the red part of the spectrum). This color is emitted by warm hydrogen, and is preferentially under the influence of the Sun’s magnetism. You can see arching prominences – huge towers of gas – off the edge of the Sun. The long stringy bits on the face of the Sun are called filaments, and are actually the exact same thing as prominences! Prominences are filaments we see from the side, instead of looking down on them. The terminology is a holdover from when astronomers first started observing the Sun, and we’re kinda stuck with it.

Also, Andre inverted the picture, so what looks black is actually very bright, and what looks bright is very dark. Those bright white blotches? Sunspots. For some reason, our brains can pick out detail better that way, and it also gives an eerie 3D sense to the image. He made a close-up mosaic of his pictures, too, which is actually a bit creepy. It’ll keep the Halloween spirit going for another day, at least!

Image credit: Andre van der Hoeven, used by permission.

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CATEGORIZED UNDER: Astronomy, Pretty pictures

The raw power of the Sun

By Phil Plait | October 19, 2012 11:00 am

Early this morning, while you were sleeping, or working, or reading Twitter, the Sun had different plans: it erupted, blasting an immense tower of plasma upward off its surface:

[Click to enheliosenate.]

This image was taken by NASA’s Solar Dynamic Observatory at 08:15 UTC this morning. The scale of it is staggering. The Sun is 1.4 million kilometers across – 860,000 miles – so this plume was at least 400,000 km long. Going back through the images, it had been brewing for hours, but really got its start around 05:00, meaning it erupted upwards at well over 100,000 km per hour. That’s fast enough to cross the face of our planet in less than 8 minutes.

By the way, did I mention the total mass of such a prominence is billions of tons? And the Sun does this kind of thing all the time.

We’re in no real danger from an eruption like this, especially this one: it’s on the Sun’s limb, so it was heading away from us. But these events can trigger storms like coronal mass ejections, where billions of tons of material is sent hurtling across the solar system at mind-crushing speeds. Those can interact with our magnetic field, creating havoc with our satellites and causing power outages.

But that’s why we keep an eye – many eyes, in fact – on our Sun. Never forget: our Sun is a star, with all the power and fury that implies. The better we understand it, the better we can protect ourselves from it when it gets angry.

Image credit: NASA/SDO. Tip o’ the welder’s glasses to Camilla SDO.

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MORE ABOUT: prominence, SDO, solar storm, Sun

STEREO catches an eruptive prominence

By Phil Plait | October 15, 2012 12:27 pm

Via Jenny Winder on Google+ I saw this way cool video of an eruptive prominence on the Sun: a towering arc of plasma held aloft by the Sun’s magnetic fields. Sometimes these field lines are unstable, and the plasma can blast away from the Sun and out into space:

This video was taken by one of NASA’s twin STEREO spacecraft; a pair of probes with one orbiting well ahead and the other behind the Earth. They stare at the Sun, literally giving us an angle on it we can’t get from our planet. Specifically this was from the STEREO Ahead spacecraft, and combines an ultraviolet view of the Sun itself together with a visible light portion that shows the Sun’s outer atmosphere, called the corona.

You can see the prominence form, rise up, and then erupt away into space over the course of one day, on October 6-7, 2012. Sometimes this material rains back down to the surface, and sometimes it escapes entirely. When it does the latter, it can flow outward, impact the Earth, and cause a geomagnetic storm. Usually those do us no harm, though if they get big they can disrupt satellites and potentially cause power outages. More likely they just create gorgeous aurorae which can be photographed from the ground.

It’s actually rather amazing how many space-based eyes we have on the Sun and the amount of data they send back. The Sun is a feisty beast, and getting feistier as we approach the maximum part of its magnetic cycle. The more we observe it, the more we learn, and learning is always good.

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CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Since the beginning of time, man has yearned to destroy the sun.

By Phil Plait | April 30, 2012 11:30 am

The Sun is feisty. Rising and falling packets of ionized gas (called plasma) below its surface generate fierce magnetic fields, which store vast amounts of energy. This can give rise to such features as sunspots, explosions like flares and coronal mass ejections, and huge, towering plumes of plasma called prominences.

While observing the Sun yesterday, April 29, my pal and friend of the BA Blog Alan Friedman captured an amazing sequence of shots of an eruptive prominence, one that doesn’t simply fall back down to the solar surface, but also blasts material out into space:

[Click to greatly enfilamentate.]

Wow! Alan estimates that at its peak the eruption was 150,000+ kilometers (100,000 miles) in height — compare that to the size of the Earth, a mere 13,000 km (8000 miles) in diameter. Yowza.

He also made a color image of it which is lovely and terrifying…. and slightly familiar. It didn’t take me long to recognize it. That treacherous profile, that conniving nose, that sinister haircut…

Oh, it’s clear who’s really behind this eruption:


[UPDATE: Good news, everyone! When I posted this on Google+, commenter Artemis Entreri mentioned it looks more like Professor Farnsworth. I can’t believe I didn’t think of that myself! I blame Wernstrom.]

Image credit: Alan Friedman, used by permission; The Simpsons™ & © Twentieth Century Fox Film Corp. All Rights Reserved. Used under The Fair Use Act. And yes, I’ll admit it looks more like Abe Simpson than Burns, but if I used Abe I could’t write the headline I did. And the nose is definitely Burns’. Also? BURNS. Because it’s hot. So clearly this was the correct choice.

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Rain on the Sun

By Phil Plait | April 19, 2012 12:16 pm

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.

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CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

GORGEOUS solar eruption!

By Phil Plait | April 16, 2012 4:22 pm

Right now as I write this, the Sun is settling down after a minor flare tripped a flippin’ huge and spectacular prominence: a looping tower of plasma hundreds of thousands of kilometers high! Using Helioviewer.org, I created a short movie of the eruption, and you just have to see it. Make sure you have the resolution set to hi-def!

Isn’t that amazing? The flare that triggered this event was no big deal, about an M1.7, which is nothing to worry about at all. We had far bigger ones in March! But that arc of plasma — ionized gas — is astonishing. Flares happen when the magnetic field lines of the Sun get tangled, and suddenly release their vast, vast stored energy. The erupting plasma follows those field lines up and away from the Sun. Some escapes forever, and some falls back to the surface. You can easily see it flowing in these videos.

These views show the eruption in two different wavelengths, though both are in the ultraviolet, where the magnetic activity is easiest to see. My friends at NASA Goddard put up some fantastic pictures of it, like the one above [click to embiggen]. They have some video there, too.

I’ll note that the active region shown here is on the side of the Sun rotating toward the Earth right now, so if there are more eruptions in the next few days we may see some affect on Earth, like aurorae at northern latitudes. As usual, you don’t need to panic about this stuff. The worst it can realistically do here on Earth is cause blackouts if a particularly big storm overloads our power grid. And while that would be irritating, it’s unlikely. So sit back and enjoy the show!

[Edited to add: Some folks are asking how long this event took; it went from start to finish in just a few hours. Another common question is how big the Earth would be compared to this, and the answer is: really really teeny. Check out the curve of the Sun’s edge, and remember that the Sun is over 100 times the diameter of the Earth!]

Credits: NASA/SDO/helioviewer.org. Music: “Feral Chase” by Kevin MacLeod.

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MORE ABOUT: flare, prominence, SDO, Sun

Desktop Project Part 8: From filament to prominence

By Phil Plait | April 2, 2012 7:00 am

[Over the past few weeks, I’ve collected a metric ton of cool pictures to post, but somehow have never gotten around to actually posting them. Sometimes I was too busy, sometimes too lazy, sometimes they just fell by the wayside… but I decided my computer’s desktop was getting cluttered, and I’ll never clean it up without some sort of incentive. I’ve therefore made a pact with myself to post one of the pictures with an abbreviated description every day until they’re gone, thus cleaning up my desktop, showing you neat and/or beautiful pictures, and making me feel better about my work habits. Enjoy.]

Sometimes, what you see depends on how you see it.

For example, take the Sun. Imagine it as a ball of ionized gas 1.4 million kilometers in diameter, churning and roiling, with intense magnetic fields piercing its surface and causing vast eruptions of material 150,000 km across.

OK, you don’t have to imagine that, since a) that’s the way the Sun really is, and 2) I can show you a picture of it! Like this one, from astrophotographer Ted Wolfe:

That shows the Sun as it was on November 25, 2011. That towering arc is plasma — gas that has had one or more electrons stripped from its atoms — being guided by the crazy strong and complex magnetic fields looping into and out of the Sun’s surface. This picture is interesting, since this loop of plasma is nearly aligned with our line-of-sight. One foot of it is on the near side of the Sun, and it arcs over across the Sun’s limb to the other side!

What’s funny is that when you get one of these on the face of the Sun it’s called a filament. When it’s seen projected against the black of space, it’s called a prominence. This terminology is a holdover from a long time ago, but we still use it. To be fair, the terminology comes up because usually filaments look very different than prominences. If you use a regular filter (one that just blocks light) to take pictures of the Sun, filaments look dark; they are cooler than the Sun’s surface and absorb the light from coming up from beneath (much like sunspots). But they’re still plenty hot, and look bright when seen against the black of space. You can see examples of this here and here.

This picture from Ted Wolfe is different. He used a special Hα filter, which doesn’t just darken the Sun but picks out a very specific color of light (in the red part of the spectrum) and isolates that, letting it through while blocking everything else. Warm hydrogen (like in the filament) emits that color, so if you use that filter the loop of plasma looks pretty much the same against the Sun as it does against the sky. It’s a bit of a trick, but is useful in showing that filaments and prominences are just two different views of the same structure.

So what do we call this thing in Ted’s picture? We see it against the Sun and against space! A filanence? A prominent? Beats me. But it’s pretty cool either way.

Credits: Tom Wolfe, used by permission.

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CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: filament, prominence, Sun

The Sun decided to blow off a little steam today. Twice.

By Phil Plait | March 23, 2012 4:20 pm

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.

Camilla Corona SDO — the Solar Dynamics Observatory’s unofficial official mascot — posted a nice video of the two eruptions:

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!

CATEGORIZED UNDER: Astronomy, Cool stuff

Top 14 Solar System Pictures of 2011

By Phil Plait | December 8, 2011 6:30 am

The Sun blows some gas to Venus

By Phil Plait | November 25, 2011 7:02 am

On November 15, the Sun had a minor eruption on its surface that launched a prominence — a towering arc of ionized gas — into space. Sometimes these prominences collapse back down to the surface, and sometimes they wind up ejecting that material into space. This one did a little of both:

The animation was made from images taken over the course of 13 hours by the Solar Dynamics Observatory. The images are false-color; what you see as orange is really ultraviolet light, where the energized gas glows brilliantly. This particular event sent some gas more or less toward Venus, where probably not much will happen. This isn’t like a major flare or coronal mass ejection… but it’s still cool.

Prominences occur all the time (click the picture here to see a gorgeous one from last year), and generally don’t wind up affecting us here on Earth. Still, it’s fascinating to watch the gas — which is hot enough to have its electrons stripped off its atoms, so it follows the Sun’s magnetic field as strongly or even more strongly than it does the Sun’s gravitational field — writhe and seethe under these tremendous forces.


CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: prominence, SDO, Sun, ultraviolet

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