Sun's tenuous outer tendrils revealed in spectacular movies from European Solar Telescope

April 30, 2015
The Sun by the Atmospheric Imaging Assembly of NASA's Solar Dynamics Observatory. Credit: NASA

New and exciting extreme ultraviolet views of the Sun's high corona from ESA's PROBA2 mission reveal mysteriously beautiful, tenuous structure extending surprisingly far from the Sun itself. The spectacular movies from the Royal Observatory of Belgium's SWAP instrument on the ESA technology demonstration testbed PROBA2, revealing previously unseen feathery structure in the region where the solar wind is accelerated, were presented today at the Triennial Earth-Sun Summit (TESS) meeting between the American Astronomical Society's Solar Physics Division (AAS/SPD) and the American Geophysical Union's Space Physics and Aeronomy section (AGU/SPA) in Indianapolis, Ind.

EUV images of the Sun's dynamic corona, with its dramatic eruptions and bright network of magnetic loops, have become familiar thanks to telescopes on space-based observatories like the 20 year-old Solar and Heliospheric Observatory (SOHO) and the more recent Solar Dynamics Observatory (SDO). But new movies from the SWAP telescope on PROBA2, a European mini-satellite launched in November 2009, reveal a new and surprising picture of this region. While SWAP also sees the hot magnetic loops glowing in ultraviolet in the low corona that these other observatories revealed, new observations show that overlying these more familiar features is a region dominated by tenuous, filamentary structures that wrap around loops and voids in the low corona and extend outwards and into interplanetary space.

While the low corona is the domain of dynamic events like solar flares, which can heat the surrounding plasma to tens of millions of degrees, the new observations from SWAP reveal a slowly evolving, much more stable region where the connection between the Sun itself and the that fills interplanetary space is born. SWAP observations reveal surprisingly long-lived fan-shaped structures that extend to heights larger than 700,000 km above the Sun's surface—structures that are, in some cases, larger than the Sun itself. Understanding what physical processes are responsible for the formation of these structures is key to determining the nature of the complex relationship between the corona and the solar wind.

The video will load shortly.
SWAP movie showing three solar rotations from mid-2014.

"Over the past few years, SWAP has observed an increasing number of these bright, fan-like structures that extend up to a million kilometers from the Sun" said Dr. Daniel Seaton, lead scientist for the SWAP instrument at the Royal Observatory of Belgium. "These fans are linked to structures we sometimes see at even greater heights in white light observations from coronagraphs and eclipses, but just as often they appear to behave very differently. They sometimes curve dramatically towards the solar poles and wrap around intense bundles of coiled magnetic field and cool, dense plasma called prominences."

Seen in time-lapse movies from the SWAP imager, the effect is striking, revealing a vivid, three-dimensional corona unlike anything solar physicists have observed before.

The new observations might also provide clues to unraveling the unusual behavior of the Sun's magnetic activity cycle, a 22-year cycle of magnetic activity and inactivity that in recent years has confounded solar scientists' expectations. Typically, the Sun goes through a highly predictable evolution from quiet, to active, and back again as its magnetic field evolves. The present cycle was slow to rise and has not produced nearly as much activity as previous cycles. At the same time, the Sun's northern and southern hemispheres, which typically evolve independently to some extent, have become almost completely decoupled.

The video will load shortly.
SWAP movie showing three solar rotations from late 2014, including the large active region responsible for the biggest outbreak of solar flares in the present solar cycle.

The new SWAP movies of the long-term evolution of the EUV corona over the rising phase of solar cycle 24 reveals clear links to both the sunspot number, a key indicator of solar activity, and the discordant activity of the two hemispheres. Unusually, the activity of the low solar atmosphere has been largely dominated by a single hemisphere, the north, whose activity has also manifested far from the solar surface. The new analysis of the bright, fan-like structures that dominate the SWAP observations has revealed some of the reasons for their appearance, which has been linked with the rise of solar activity in the past five years. The analysis also helps explain why fans occasionally disappear from the observations as well.

"These EUV coronal fans seem to be rooted in low-latitude magnetic regions without sunspots, and they trace open magnetic field lines overlying closed arcades linking to the solar pole. As soon as new magnetic flux emerges near the magnetic sheet foot points, the fans break down," said Anik De Groof, a scientist at the European Space Agency who led the latest analysis of these observations. "The fact that the fans primarily appear in the northern hemisphere may be related to the rather unusual polar magnetic field reversal in Cycle 24. However, more data and analysis of both SWAP and measurements will be needed to give a firm conclusion."

Whatever clues the new observations might offer to the nature of the evolution of , for scientists they raise as many questions as they answer, questions they hope upcoming solar missions will answer. PROBA2's sister mission, PROBA3, will observe the same innermost region of solar corona in white light using two spacecraft, flying in formation, to generate an artificial eclipse. Solar Orbiter, meanwhile, will leave Earth orbit altogether, flying out of the ecliptic to higher solar latitudes to observe the Sun's poles at a distance inside the orbit of Mercury to reveal the magnetic structure of the region where many of the fan structures seen by SWAP are anchored.

Explore further: Image: Solar corona viewed by Proba-2

More information: * "SWAP Observations of the Long-Term, Large-Scale Evolution of the Extreme-Ultraviolet Solar Corona." Seaton, D. B., De Groof, A. et al., 2013 November 1, Astrophysical Journal, Vol. 777, No. 1. dx.doi.org/10.1088/0004-637X/777/1/72, arxiv.org/abs/1309.1345

* "Observations of a Hybrid Double-Streamer/Pseudostreamer in the Solar Corona," L. A. Rachmeler et al., 2014 May 20, Astrophysical Journal Letters, Vol. 787, No. 1 dx.doi.org/10.1088/2041-8205/787/1/L3, arxiv.org/abs/1312.3153

Related Stories

Image: Solar corona viewed by Proba-2

March 17, 2015

This snapshot of our constantly changing Sun catches looping filaments and energetic eruptions on their outward journey from our star's turbulent surface.

NASA's SDO sees two coronal holes

March 18, 2015

NASA's Solar Dynamics Observatory, or SDO, captured this solar image on March 16, 2015, which clearly shows two dark patches, known as coronal holes. The larger coronal hole of the two, near the southern pole, covers an estimated ...

Large coronal hole near the sun's north pole

July 20, 2013

The European Space Agency/NASA Solar and Heliospheric Observatory, or SOHO, captured this image of a gigantic coronal hole hovering over the sun's north pole on July 18, 2013, at 9:06 a.m. EDT. Coronal holes are dark, low ...

Image: Giant filament seen on the sun

February 12, 2015

A dark, snaking line across the lower half of the sun in this Feb. 10, 2015 image from NASA's Solar Dynamics Observatory (SDO) shows a filament of solar material hovering above the sun's surface. SDO shows colder material ...

Recommended for you

Dawn mission extended at Ceres

October 20, 2017

NASA has authorized a second extension of the Dawn mission at Ceres, the largest object in the asteroid belt between Mars and Jupiter. During this extension, the spacecraft will descend to lower altitudes than ever before ...

10 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

cantdrive85
1 / 5 (3) Apr 30, 2015
"Open field lines"?!?!

This guy obviously learned his EM theory from an astrophysics course. Only in astrophysics does magnetism occur from magic, the rest of physics understands electric currents and electric fields cause magnetism. Well, except for the magic bowl guy.
reset
4.2 / 5 (5) May 01, 2015
the rest of physics understands electric currents and electric fields cause magnetism.


So you finally have evidence of an electric current forming on it's own, without "help"? I mean yes we all understand the second order effect of an electric current producing a magneitic field perpendicular to the current flow, and yes we all understand how unpaired electron orbits generate magnetic flux exterior to ferromagnetic materials...but you now have the holy grail right?...the final exclamation point on the EU theory. After years and years of staring at a magnetless vacuum chamber housing an opaque cloud of charged particles...you finally observed a current form. Can't wait to see the video....

For some reason I keep having to confine and align SA particles with some physical mechanism to create a current....or a plasmoid...or a jet....or a torus. How dammit? How did you get to watch them do it by themselves...it shoulda been me....you lucky SOB.
reset
4.2 / 5 (5) May 01, 2015
Oh wait...you were just saying the same thing you have been saying for several years...still with no way to back it up.....because there will never be a way to back it up....because it is contrary to the ACTUAL laws of physics....you poor unlucky SOB.

Rant on EU boy...rant on.
cantdrive85
1 / 5 (3) May 01, 2015
So you finally have evidence of an electric current forming on it's own, without "help"?


This is a condition you insist I or the EU has made claims about, it is in your own mind.

Please explain to me how LaPointe magnetizes those magic bowls without electricity.

And as I've mentioned before, your opaque cloud is part of your circuit. As such the current is flowing through it, however weak it happens to be. That's why it glows!
TheGhostofOtto1923
1 / 5 (2) May 01, 2015
Huh. Sure looks like a whole lotta magnetism goin on there dont it?
SuperThunderRocketJockey
5 / 5 (1) May 01, 2015
The Sun's just courting Proxima Centauri, showing off its plumage.
RealityCheck
1 / 5 (2) May 01, 2015
Hi reset, cantdrive, everyone. :)

Perhaps it would be helpful to your discussions of the subject if all concerned could take time out to refresh understandings regarding ramifications of Chaos Theory of perpetual dynamics as applied to the energy space at its most fundamental scales/processes (as manifest by the Quantum Vacuum processes and features phenomena at the observable scales). There are two ways to generate a 'magnetic phenomena': one way is motion of charged particles moved by random chaotic motions at quantum levels, whose directional force tendencies (or 'flows') may coincide in same direction either transiently (such as virtual particle in quantum vacuum perturbations etc) or persistently (such as in electron/proton and permanent magnets); and the other way is via spatially extended 'flows' of charged matter quanta like we observe in plasma 'flows/currents' influenced by both gravity and chaotic internal/external plasma stream interactions. Can't say more for now. Bye!
reset
5 / 5 (2) May 04, 2015
So you finally have evidence of an electric current forming on it's own, without "help"?


This is a condition you insist I or the EU has made claims about, it is in your own mind.


From your first post in this thread genius....

the rest of physics understands electric currents and electric fields cause magnetism.


Please explain to me how LaPointe magnetizes those magic bowls without electricity.


They are Ferromagnetic EU boy, thats the one where there is no electric field.

And as I've mentioned before, your opaque cloud is part of your circuit. As such the current is flowing through it, however weak it happens to be. That's why it glows!


No, it glows because the gas has been ionized, enough energy has been added to neutral atoms to cause electrons to depart the atomic structure - - ionization. The glow are photons given off because the SA particles "vibrate", not because they form a current.
cantdrive85
1 / 5 (2) May 04, 2015
They are Ferromagnetic EU boy, thats the one where there is no electric field.


So everything in the universe is ferromagnetic? That is the source of these pervasive magic bowls? Interesting!
reset
1 / 5 (1) May 04, 2015
They are Ferromagnetic EU boy, thats the one where there is no electric field.

So everything in the universe is ferromagnetic?


In the most literal sense possible...yes. That is why the stable SA particles which constitute the building blocks of all matter demonstrate a charge when unbound.

That is the source of these pervasive magic bowls? Interesting!


What is the "source" of charge?

You are confused about what Lapoints theory says. The bowls are a revision to the theory of the structured magnetic moment, that is all. Instead of the "bar magnet" field, experimentation and a mind boggling amount of observation point to a "bowl" structured field of flux . That the bowls experimentally produce all of the particle structures that the mainstream can't explain was the reason the EU cronies dove all over it. Then took it personally when he told them their theory, fundamentally, is wrong. He doesn't claim to know the source of "charge"....are you?

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.