Giant sunspot returns – and it's bigger and badder than ever

November 12, 2014 by Paul Cally, The Conversation
Ten Earths could be laid across the diameter of the gigantic sunspot in AR2191 during its previous rotation – captured on October 23, 2014. Credit: NASA’s Solar Dynamic Observatory

The largest sunspot seen in 24 years is rotating back to face the Earth, and it looks to have grown even bigger.

Last month, the solar active region known as AR12192 (also known as AR2192 to some of its friends) entertained the world with the sunspot clearly visible with the naked eye (with some appropriate and approved solar-watch or eclipse dark glasses, of course), and produced a series of large flares.

But after spending some time over on the far side of the sun, it hasn't finished impressing us yet.

AR12192 is due to rotate back onto our side of the sun today (November 12) and and it has grown. Because of its size, the leading edge would actually have appeared about a day earlier.

Charles Lindsey, of North West Research Associates (NWRA) in Boulder Colorado (and a frequent visitor to Monash University in Australia), has been following the progress of AR12192 since it disappeared around the west limb of the sun a couple of weeks ago, and found that it has grown significantly.

The sun rotates about once every 27 days as viewed from the Earth, so we haven't been able to see AR12192 directly since then. But using the helioseismology technique acoustic holography that Dr Lindsey and his colleague Doug Braun developed, they can "see" large active regions on the far side by computationally regressing oscillations (waves) observed on the nearside back to their sources.

Drs Lindsey and Braun's far side imaging technique is now routinely used to keep an eye on active regions popping up or developing on the other side of the sun. The image (above) shows a seismic reconstruction of the far side (in yellow) with a very clear and very large active region in the southern hemisphere. This is AR12192.

Why all the activity?

So, what is an , and how does it relate to sunspots? Active regions are huge agglomerations of magnetic field that bubble up to the surface from deep in the sun's interior.

Sunspots are the areas of strongest field, up to about 3,000 Gauss. To put that in context, the Earth's magnetic field is around half a Gauss.

Far side image of AR12192 in the yellow tinted section which we only ‘see’ using helioseismology. Credit: Stanford University’s Joint Science Operations Center

The magnetic field largely inhibits the boiling convection normally seen across the solar surface. Convection is the mechanism that carries most of the energy from the nuclear furnace in the core through the outer 29% of the sun.

That is why sunspots appear dark; magnetism halts the conveyor belt.

The is currently near the maximum of Solar Cycle 24 – the 24th cycle of solar activity since detailed recording began in 1755. Sunspot number rises and falls on a roughly 11-year cycle, and although Cycle 24 is very weak compared to others in the last century, it can still produce a doozy of a spot.

But active regions don't just give us sunspots. They also produce flares, the most energetic events in the solar system.

Flares occur when the complex twists and stretches to such an extent that it snaps, like a rubber band breaking, and then reconnects to other field lines.

This releases huge bursts of energy over several minutes, up to 6×1025 Joules for the largest X-class flares. This is about 100,000 times the total energy usage of humans in a full year.

Coronal mass ejections (CMEs) also commonly emerge from active regions. These are massive bubbles of gas, weighing as much as 100 billion kg, that burst into space at up to 1,000 km per second, carrying huge loads of charged particles and magnetic flux.

CMEs are often – though not always – associated with flares, and flares may or may not have accompanying CMEs. A flare that doesn't is termed "ordinary".

On its first pass, the huge AR12192 was comparable in size to Jupiter and produced several (ordinary) X-class flares and many smaller ones, but no large CMEs.

The video will load shortly

But Hugh Hudson of Space Sciences Laboratory at Berkeley, California, notes that older active regions tend to produce more CMEs, so he is expecting a big CME show this time around.

Impact on Earth

But what does this mean for us on Earth? CMEs in particular can have a massive impact on the Earth's magnetosphere, causing stunning aurorae, power blackouts, interruptions to telecommunications and damage to satellites in orbit.

The so-called Carrington flare of 1859 produced aurorae visible in Queensland, and damaged telegraph stations around the world. Our modern technological world is far more vulnerable.

The bright light in the centre of the image shows an X-class solar flare on October 26, 2014. This was the third X-class flare in 48 hours. Credit: NASA’s Solar Dynamic Observatory

So, if AR12192 launches any large CMEs in our direction when it comes around to our side, we'd better batten down the hatches.

That can mean disconnecting long-distance power grids, placing satellites in safe mode and rerouting aircraft on polar routes.

Explore further: NASA's SDO sees giant January sunspots

Related Stories

NASA's SDO sees giant January sunspots

January 7, 2014

An enormous sunspot, labeled AR1944, slipped into view over the sun's left horizon late on Jan. 1, 2014. The sunspot steadily moved toward the right, along with the rotation of the sun, and now sits almost dead center, as ...

Giant sunspot makes third trip across the sun

February 28, 2014

a magnetically strong and complex region on the sun's surface – has just appeared over the sun's horizon. This is the third trip for this region across the face of the sun, which takes approximately 27 days to make a complete ...

The difference between CMEs and solar flares

September 23, 2014

This is a question we are often asked: what is the difference between a coronal mass ejection (CME) and a solar flare? We discussed it in a recent astrophoto post, but today NASA put out a video with amazing graphics that ...

Partial solar eclipse shows off massive sunspot

October 27, 2014

Astronomers with the National Science Foundation (NSF)-funded National Optical Astronomy Observatory (NOAO) captured pictures not only of Thursday's partial solar eclipse, but also of the "monster" sized active region or ...

Tracking a gigantic sunspot across the Sun

October 31, 2014

An active region on the sun – an area of intense and complex magnetic fields – rotated into view on Oct. 18, 2014. Labeled AR 12192, it soon grew into the largest such region in 24 years, and fired off 10 sizable solar ...

Recommended for you

Milky way had a blowout bash six million years ago

August 29, 2016

The center of the Milky Way galaxy is currently a quiet place where a supermassive black hole slumbers, only occasionally slurping small sips of hydrogen gas. But it wasn't always this way. A new study shows that 6 million ...

Hubble spots an irregular island in a sea of space

August 29, 2016

This image, courtesy of the NASA/ESA Hubble Space Telescope's Advanced Camera for Surveys (ACS), captures the glow of distant stars within NGC 5264, a dwarf galaxy located just over 15 million light-years away in the constellation ...

NASA's Juno successfully completes Jupiter flyby

August 29, 2016

NASA's Juno mission successfully executed its first of 36 orbital flybys of Jupiter today. The time of closest approach with the gas-giant world was 6:44 a.m. PDT (9:44 a.m. EDT, 13:44 UTC) when Juno passed about 2,600 miles ...

10 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

automaticsteam
1 / 5 (8) Nov 12, 2014
"Science is missing larger systems. The Sun-Earth synergy, complete with feedback loops and vortices, is exciting both Earth and Sun. It could be said they are playing off of each other, and the mutual feed-in, amplifies as it reverberates. This is cyclical, and life-changing. This is not calming down anytime soon." Tectonic Revolution (...or The Advent of the Tectonicene Epoch) c.2014

I need scientists who wish to look at this to contact me, my mail is at yahoo and my name is automaticsteam

joerocker66
5 / 5 (6) Nov 13, 2014
The earth is way too small for it to provide any significant feedback to the sun. If the sun were a basketball, the earth would be a BB about 100ft away. How much influence do YOU think it has? Is there some, of course, does it matter "at our level"? Probably not...I will not say there is none.
cantdrive85
1 / 5 (6) Nov 13, 2014
The earth is way too small for it to provide any significant feedback to the sun. If the sun were a basketball, the earth would be a BB about 100ft away. How much influence do YOU think it has? Is there some, of course, does it matter "at our level"? Probably not...I will not say there is none.

This is the same type of reasoning which people used to deny the possibility that a virus or bacteria could cause illness. We know this is not the case though.
barakn
5 / 5 (7) Nov 13, 2014
No reason given by automaticsteam why Earth in particular is responsible for the feedback loops when there are so many other planets, especially Jupiter with it's faster rotation rate, magnetic field 14x stronger than Earth's, etc.. If someone were to actually contact this individual, I suspect they'd findt that the energy of the pyramids, hidden Atlantis technology, or other woowoo are involved.
Uncle Ira
4 / 5 (8) Nov 13, 2014
We know this is not the case though.


Maybe these bigger and badder sunspots will dig us another grand canyon to go the one we got now.
Modernmystic
5 / 5 (6) Nov 13, 2014
The earth is way too small for it to provide any significant feedback to the sun. If the sun were a basketball, the earth would be a BB about 100ft away. How much influence do YOU think it has? Is there some, of course, does it matter "at our level"? Probably not...I will not say there is none.

This is the same type of reasoning which people used to deny the possibility that a virus or bacteria could cause illness. We know this is not the case though.


Biology and astrophysics aren't equivalent.
cantdrive85
1 / 5 (5) Nov 13, 2014
The earth is way too small for it to provide any significant feedback to the sun. If the sun were a basketball, the earth would be a BB about 100ft away. How much influence do YOU think it has? Is there some, of course, does it matter "at our level"? Probably not...I will not say there is none.

This is the same type of reasoning which people used to deny the possibility that a virus or bacteria could cause illness. We know this is not the case though.


Biology and astrophysics aren't equivalent.

It's an analogy in regards to complex systems and how small parts of that system can affect the whole.
Modernmystic
5 / 5 (4) Nov 14, 2014
The earth is way too small for it to provide any significant feedback to the sun. If the sun were a basketball, the earth would be a BB about 100ft away. How much influence do YOU think it has? Is there some, of course, does it matter "at our level"? Probably not...I will not say there is none.

This is the same type of reasoning which people used to deny the possibility that a virus or bacteria could cause illness. We know this is not the case though.


Biology and astrophysics aren't equivalent.

It's an analogy in regards to complex systems and how small parts of that system can affect the whole.


Yeah, it's a bad analogy...
adam_russell_9615
5 / 5 (1) Nov 16, 2014
"Science is missing larger systems. The Sun-Earth synergy, complete with feedback loops and vortices, is exciting both Earth and Sun. It could be said they are playing off of each other, and the mutual feed-in, amplifies as it reverberates. This is cyclical, and life-changing. This is not calming down anytime soon." Tectonic Revolution (...or The Advent of the Tectonicene Epoch) c.2014

I need scientists who wish to look at this to contact me, my mail is at yahoo and my name is automaticsteam


What "feedback loop" are you talking about? What mechanism? Are you saying the magnetic fields stretch that far? Do you have any actual math to back up that claim?
movementiseternal
Nov 17, 2014
This comment has been removed by a moderator.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.