Tag: sunspots

What a dramatic sunspot!

By Phil Plait | June 14, 2012 12:07 pm

Active sunspots are pretty dramatic all by themselves, but a little over-the-top music can’t hurt.

This spot has been spitting out some low-level activity, but the Sun is tricksy. We’ll see if we get some bigger ones as this thing rotates in our direction over the next few days. Be on alert for aurorae!

[Footage by NASA's Solar Dynamics Observatory]

Related Posts:

- GORGEOUS solar eruption!
- The Sun decided to blow off a little steam today. Twice.
- The Sun’s angry red spot
- HD footage of last night’s flare

CATEGORIZED UNDER: Astronomy, Cool stuff, NASA

Solar Cinco de Mayo

By Phil Plait | May 8, 2012 10:25 am

Alan Friedman is a photographer who takes amazing pictures of the Sun. While others were out celebrating Cinco de Mayo this past weekend, he was outside taking another jaw-dropping image of the nearest star in the Universe:

Yegads! Click to ensolarnate, and he has a greyscale version, too.

I love the detail and texture of his images. He has an excellent telescopic setup which yields the superb resolution, and he employs an old trick to get the texture: he inverts the image of the Sun’s disk, making black stuff look white and vice-versa. This is a technique that’s been used by astronomers for decades to enhance images; our eyes see details better that way. When Alan does it, I swear it makes the Sun look like a 1.4 million-kilometer-wide shag rug.

All the way on the left, just on the Sun’s edge, you can see a group of sunspots just rotating into view. That’s Active Region 1476, and Alan provided me with a clear picture of them (no tom-foolery) which I’ve put here. That monster group is about 100,000 kilometers (60,000 miles) across, so when I saw them I immediately suspected trouble.

… and sure enough, they had a medium-sized eruption just this morning. At 13:00 UTC they blasted off an M1.4 class flare; big enough to potentially cause some radio disruption and maybe some aurorae. NASA’s Solar Dynamics Observatory got a dramatic view of the eruption:

Flares this size are relatively common; there was one in late March for example. Bigger ones happen less frequently, though again we did see one 50 times this powerful in March as well! We’ll have to see if today’s eruption will cause any aurorae, and either way, we should keep our eyes on AR1476.

Image credit: Alan Friedman, used by permission. Tip o’ the Sun visor to Camilla Corona SDO on Google+ for the video.

Related Posts:

- NASA’s guide to solar flares
- The Sun unleashes an X5.4 class flare
- The Sun’s Angry Red Spot
- The boiling, erupting Sun (to this day my favorite photo by Alan!)

CATEGORIZED UNDER: Astronomy, Pretty pictures

The Sun's angry red spot

By Phil Plait | March 15, 2012 7:00 am

The Sun has been in a bit of a mood lately, spitting out some pretty big flares (including the second largest one of the current magnetic cycle). Alan Friedman, one of my favorite astrophotographers, caught the culprit sunspot, Active Region 1429, as it was nearing the edge of the Sun on Monday:

Doesn’t look like your normal shot of the Sun, does it? [Click to ensolarnate.]

Alan uses an Hα filter, which cuts out almost all the light from the Sun except for a narrow slice of color emitted by warm hydrogen. This reduces the glare hugely, and reveals delicate structures in the Sun’s plasma. He then inverts the image, so bright things appear dark, and vice-versa. That’s an old astronomer’s trick that makes fainter things easier to see. He also used a false color palette to make it appear reddish. That’s actually a good idea, since the color of light emitted by the hydrogen is at 6563 Angstroms, right in the middle of the red part of the spectrum!

In this case, doing all this makes the Sun look like a 1970s shag rug. It’s a technique he uses to great effect. Just click on the Related Posts links below to see how!

Andf you’re wondering what the whole Sun looked like instead of just this closeup, then feast your eyes on this:

Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Giant sunspots are giant

By Phil Plait | November 9, 2011 8:40 am

Active Region 1339 — a huge cluster of sunspots which appeared on the Sun a few days ago — is still going strong. "Amateur" astronomer Alan Friedman took a devastating picture of the 100,000 km-wide-grouping:

[Click to embiggen.]

This picture was taken using an Hα filter, which picks out the light from warm hydrogen, and really shows the texture of the solar surface. I added the Earth in there just to give you a taste of how fracking huge this cluster is; the scale should be pretty close. Obviously, several of the individual spots in AR 1339 are as big or bigger than our entire planet, in case you happened to feel too big for your britches today.

… but still. The thing is, we’re starting to understand sunspots, better than any time in human history before us. Heck, a few centuries ago most people didn’t know sunspots even existed, and if you had said they did — violating the Aristotelian perfection of the heavens — they would’ve laughed at you. If you were lucky. Some folks had a really hard time dropping Aristotle’s influence.

And not only that, we can now routinely capture incredible images of these spots and present them on the internet, where an entire planet can see them and gasp at their size and beauty. I posted my own imaging attempts on Google+ last weekend, for that matter.

Chinese curses be damned: we do live in interesting times, and I’m glad. I wouldn’t have it any other way.

Image credit: Alan Friedman, used by permission.

Related posts:

- For your viewing pleasure: Active Region 1302
- Seriously jaw-dropping picture of the Sun
- The boiling, erupting Sun
- The birth of a sunspot cluster

HUGE sunspots turning toward Earth

By Phil Plait | November 6, 2011 7:00 am

As the Sun rotates roughly once per month, we see different features come into view… and the latest is an enormous sunspot system which just came around the limb of the Sun:

[Click to magneticfieldentanglenate.]

That shot was taken by the Mexican "amateur" astronomer César Cantú, and shows the spots — called Active Region 1339 — from November 4. The size of this system is staggering; the whole thing is well over 100,000 km (60,000 miles) across, and the dark cores are each about the size of our entire Earth!

They’re active, too: On November 3rd they popped off a pretty big X 1.9 class flare:

That image was taken by NASA’s Solar Dynamics Observatory in the ultraviolet, where violent activity is easier to see. NASA made a video of the flare, and you should take a look. It’s pretty amazing.

So we have a recipe for some action here: big spots, known to be active, and they’re riding the Sun’s surface as it rotates them more fully toward us. Over the next week and a half we might get some more flares from them, and maybe some coronal mass ejections… and that means we might get more aurorae. Stay tuned here; if any occur I’ll report them as soon as I hear. Also keep your browser pointed at SpaceWeather.com, which always has the latest info as well.

Image credits: César Cantú; NASA/SDO

Related posts:

- October’s solar blast, seen from the side
- Gorgeous aurorae
- Solar purrominence
- Gorgeous flowing plasma fountain erupts from the Sun

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Gorgeous flowing plasma fountain erupts from the Sun

By Phil Plait | October 10, 2011 7:00 am

On September 24th, Active Region 1302 — a cluster of enormous sunspots — popped off an X-class flare, a powerful event that caused some beautiful aurorae here on Earth.

But the flares don’t have to be so powerful to generate ethereal, magnificent beauty. A day after that biggish event, those sunspots burped again, this time with a lower-power M-class flare. Now, when I say "low power", it’s not like a firecracker or a car backfiring: the total energy released would still dwarf the combined nuclear might of every country on Earth! By a lot. But for the Sun, that’s considered to be "meh".

Still, if you get a good view of it, well, it’s still gorgeous. The Solar Dynamics Observatory, orbiting the Earth, has what is essentially a box seat to the Sun, and got this footage of the flare:

[Make sure to set it to at least 720p and make it full screen!]

The flare and prominence — the arcing tower of material — lasted about three hours, and this video shows it at a rate of one frame every minute of real time. Read More

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

Are we headed for a new ice age?

By Phil Plait | June 17, 2011 6:02 am

Much ado was made over the recent news that the Sun’s magnetic activity may be cooling off over the next few years. Can this mean the Earth itself will literally cool off, slipping into an ice age? Some news sites are reporting it that way (of course, the execrable Daily Mail uses the headline "Earth facing a mini-Ice Age ‘within ten years’ due to rare drop in sunspot activity"; which isn’t even within a glancing blow of reality).

The answer — spoiler alert! — is almost certainly "no". I want to make sure that’s clear, because I will bet essentially any amount of money that some climate change denial sites will run with this story and claim that we don’t need to worry about global warming. That’s baloney, and what follows is why. The reasons take a minute to explain, but of course that’s where the cool stuff (haha!) is. So let’s take this one step at a time. And if you have the attention span of an E. coli bacterium, you can skip down to the conclusion section.

[Note: a lot of this is taken from my book "Death from the Skies!", where I interviewed approximately a bazillion people. One in particular was Caspar Ammann, who was very helpful in explaining the solar connection with the Little Ice Age to me.]

The Quiet Sun

The Sun has a magnetic cycle, its magnetic field waxing and waning in strength roughly every 11 years. The strength and complexity of the solar field governs a lot of the surface activity, including sunspots, solar flares, prominences, and coronal mass ejections.

Right now, in 2011, we’ve just left a period of an extended minimum, and the next max is due in late 2013 and early 2014. But scientists studying the Sun have seen three independent lines of reasoning indicating that the next rise to the solar peak, in 2022 or so, may be delayed or even not occur at all. I wrote about this in an earlier post, so you can get the details there. It’s the core of the "oncoming ice age" claim, so you should read it.

I’ll note right off the bat that not everyone agrees with these findings. Doug Biesecker, a solar physicist NOAA Space Weather Prediction Center [full disclosure: Doug is an acquaintance of mine; I interviewed him for an episode of "Bad Universe" about solar storms] , has written a document calling the findings into question. It’s not exactly a rebuttal; it’s more of a warning not to over-interpret the results. He also points out that a weak cycle may not have an effect on our climate; we simply don’t know for sure.

At this point you may be asking, so what? If the Sun has fewer sunspots and no flares, what difference does that make here on Earth? And how could it possibly trigger an ice age?

Read More

The Sun may be headed for a little quiet time

By Phil Plait | June 14, 2011 11:01 am

Is the solar cycle shutting down?

New results indicate it may very well be, at least temporarily. Even though the Sun is currently approaching the peak of its cycle in 2013, and we’re seeing an increase in activity (more sunspots, flares, and other violent events), there are strong signs that the next expected peak (in 2022 or later) may be weaker, or may not come at all!

Here’s the deal. The Sun is a seething ball of ionized gas, called plasma, and has very complex magnetic fields that interact with this plasma. The overall strength and activity from the magnetic field rises and falls on roughly an 11 year cycle. When the cycle is at its minimum the field strength is weak, and we see few or no sunspots or other activity. Then, a little over five years later, the cycle peaks and there’s lots of fun stuff going on, with flares, coronal mass ejections, and more.

Scientists studying the Sun have been trying to figure out this cycle for over a century. It’s very complex, but as technology has gotten better, some trends have been found. And recently, these indicators are all pointing to the Sun settling down magnetically.

For one, there is an east/west river of gas the flows under the surface of the Sun (it can’t be seen directly, but it generates sound waves that travel from it to the surface, revealing its presence; I describe this in detail in an earlier post). This river comes and goes, but usually forms at mid-latitudes on the Sun and shifts toward the equator as the cycle progresses. As it does so, sunspots form above it. Although the next cycle won’t start for a few years, the river associated with it should already be forming. However, there are no indications it has, making astronomers think the next cycle may be delayed.

For another, scientists have found that the average magnetic strength of sunspots has been declining over the years. Sunspots form when magnetic fields inside the Sun break through the surface. Normally, rising gas from the solar interior would cool and drop back down, but due to the way the magnetic fields interact with the gas, the cool gas is prevented from dropping. Cooler gas is dimmer, so we see this as dark spots on the Sun: sunspots.

Sunspots are an intrinsically magnetic phenomenon, so this trend of weaker magnetic fields inside them may be indicating, again, the next cycle may be delayed or not come at all.

Moving farther outward yet we come to the third line of evidence of a weak upcoming cycle. The Sun has an atmosphere, called the corona, of very thin but extremely hot plasma. It too is greatly affected by magnetic fields; every cycle the magnetic activity in the corona tends to form near the Sun’s equator and then slowly move toward the poles over the next few years. This "rush to the poles", as the scientists call it, is very weak this year, and may indicate that the peak in 2013 may not be terribly active. It’s unclear what this might mean for the cycle peak after that.

So what does this mean for us? Read More

SDO's first year in space with bonus voting

By Phil Plait | April 26, 2011 7:00 am

NASA’s phenomenal Solar Dynamics Observatory has spent just over a year in space. During that time it has ceaselessly observed the Sun, returning incredibly detailed and exquisite images and videos. In high resolution we’ve seen sunspots, flares, coronal mass ejections, filaments, prominences, and towering loops of magnetic plasma.

To celebrate, the folks at SDO put together this video featuring 12 of their favorite clips. I’ve written about several of these myself in the past year (see Related Posts below). Make sure you set the resolution to 720p!

You can go to the SDO page to get a list of what you’re seeing.

In a related bit of news, NASA is asking people to vote on their favorite short video from SDO. Many of those clips are also in the above video, but they’re also listed separately on the NASA contest page. I know which one is my favorite… but I’m not telling.

The voting closes May 5th.

Related posts:

- When the Earth takes a bite out of the Sun
- An eclipse from space with a two-way Moon
- kaBLAM! Footage of the X-class solar flare
- Sunspot 1158 ain’t done yet
- First earthward-heading solar flare of the cycle
- The birth of sunspot cluster
- Arc of dissent
- A huge lopping prominence on the Sun
- The Sun blasts out a flare and a huge filament
- SDO lunar transit: now with video!

Followup: Sunspot group's loopy magnetism

By Phil Plait | April 20, 2011 7:00 am

Yesterday I posted a video showing a cluster of sunspots forming on the Sun’s surface. As it happens, a new video was released last night from NASA’s Solar Dynamics Observatory satellite showing this same sunspot group, but this time, along with the visible light images, we also get X-ray images. X-rays are emitted by plasma trapped in magnetic fields, so in a sense you can actually see the magnetism of the sunspots as they evolve. Watch!

How awesome is that? The full disk picture on the left combines visible and X-ray light, the lower right shows the spots in just visible light, and the upper right is just X-rays. You can see the magnetic field lines looping from one part of the sunspot cluster to another as the plasma follows them. If you look carefully, you’ll see flashes of brightness, too: those are solar flares!

The magnetic field stores energy. If the loops get tangled together, they can snap and release their energy in one sudden burst (like a box full of mousetraps, if you happened to see my episode of "Bad Universe" on Discovery Channel yesterday). What’s interesting about this video is that it shows that the rotation of the sunspots plays into this too.

Imagine a bunch of magnetic field lines coming from a spot, going up above the Sun’s surface, then back down to another spot. If the spot is rotating, that cluster of loops will get twisted up, just like a rubber band gets twisted when you rotate one end (do you kids these days still play with balsa wood airplanes that use a rubber band to spin the propeller? It’s just like that).

If the loops get too twisted, they’ll snap, too, and kablam! Solar flare. Remember, this was the biggest flare seen in several years, so apparently having several rotating spots feeding into the system really pumps a lot of energy into the loops. That makes sense, and it means that clusters of spots may be the ones we should keep our eyes on if we want to catch big flares in the act.

Video credit: Movie produced by D. Brown (UCLan). Data courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

Related posts:

- The birth of a sunspot cluster
- Incredible solar flare video
- Sunlight and a spot of calcium
- One solar piece of flare


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