The secret lives of solar flares

The secret lives of solar flares
Sunspots sketched by R. Carrington on Sept. 1, 1859. Credit: R. Astronomical Society.

One hundred and fifty two years ago, a man in England named Richard Carrington discovered solar flares. 

It happened at 11:18 AM on the cloudless morning of Thursday, September 1st, 1859. Just as usual on every sunny day, the 33-year-old solar astronomer was busy in his private observatory, projecting an image of the sun onto a screen and sketching what he saw. On that particular morning, he traced the outlines of an enormous group of sunspots. Suddenly, before his eyes, two brilliant beads of white light appeared over the sunspots; they were so bright he could barely stand to look at the screen.

Carrington cried out, but by the time a witness arrived minutes later, the first solar flare anyone had ever seen was fading away. 

It would not be the last. Since then, astronomers have recorded thousands of strong flares using instruments ranging from the simplest telescopes in backyard observatories to the most complex spectrometers on advanced spacecraft.  Possibly no other phenomenon in astronomy has been studied as much. 

After all that scrutiny, you might suppose that everything about would be known.  Far from it.  Researchers recently announced that solar flares have been keeping a secret.

“We’ve just learned that some flares are many times stronger than previously thought,” says University of Colorado physicist Tom Woods who led the research team. “Solar flares were already the biggest explosions in the solar system—and this discovery makes them even bigger.”

NASA’s Solar Dynamics Observatory (SDO), launched in February 2010, made the finding:  About 1 in 7 flares experience an “aftershock.”  About ninety minutes after the flare dies down, it springs to life again, producing an extra surge of extreme ultraviolet radiation. 

“We call it the ‘late phase flare,’” says Woods.   “The energy in the late phase can exceed the energy of the primary flare by as much as a factor of four.”

What causes the late phase? Solar flares happen when the magnetic fields of sunspots erupt—a process called “magnetic reconnection.”  The late phase is thought to result when some of the sunspot’s magnetic loops re-form.  A diagram prepared by team member Rachel Hock of the University of Colorado shows how it works. 

The extra energy from the late phase can have a big effect on Earth.  Extreme ultraviolet wavelengths are particularly good at heating and ionizing Earth’s upper atmosphere.  When our planet’s atmosphere is heated by extreme UV radiation, it puffs up, accelerating the decay of low-orbiting satellites.  Furthermore, the ionizing action of extreme UV can bend radio signals and disrupt the normal operation of GPS.   

SDO was able to make the discovery because of its unique ability to monitor the sun’s extreme UV output in high resolution nearly 24 hours a day, 7 days a week.  With that kind of scrutiny, it’s tough to keep a secret--even one as old as this.

The original research of Woods et al may be found in the Oct. 1, 2011, issue of the Astrophysical Journal.

Explore further

Rotating sunspots spin up a super solar flare

Provided by Science@NASA
Citation: The secret lives of solar flares (2011, September 21) retrieved 18 July 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

Sep 21, 2011
This made for quite an interesting read. Thank you Dr. Philps! (and thank you for your work at!)

Sep 21, 2011
Weve just learned that some flares are many times stronger than previously thought.

Solar flares were already the biggest explosions in the solar systemand this discovery makes them even bigger.

Thank you for citing Carrington's discovery of the flare that caused so much damage to electrical circuits on Earth in 1859 and for an update on the tremendous power of solar flares.

How deep beneath the glowing photosphere (91% H and 9% He)


Do these powerful magnetic fields originate?

a.) In the H/He atmosphere?
b.) In the metal-rich mantle?
c.) In the pulsar solar core?

In 2002, we suggested that the correct answer is b.) or c.) [1]

1. "Super-fluidity in the solar interior: Implications for solar eruptions and climate",
Journal of Fusion Energy 21, 193-198 (2002)

With kind regards,
Oliver K. Manuel

Sep 21, 2011
In 2002, we suggested that the correct answer is b.) or c.) [1]
Only you have no evidence that supports the 'suggestion' that you keep spamming the site with. Despite repeated requests for any actual evidence that supports you neither post any nor admit you are wrong.

In fact the images you use as evidence only show the expected traces of metal ions and do not support you in any way. Indeed they show you are wrong.


Sep 24, 2011
So Oliver is not interested in actual discussion again. Thus it is spam and is being reported as such.


Sep 24, 2011
Only you have no evidence that supports the 'suggestion' that you keep spamming the site with.

Those unable to comprehend the conclusions or the experimental observations reported by PhD scientists in peer-reviewed journals have a problem.

They usually identify themselves.

With kind regards,
Oliver K. Manuel
Former NASA Principal
Investigator for Apollo

Sep 25, 2011
you are just copying and pasting your nonsense again oliver. like i said before -"Yes, you sure do oliver.....we can all tell by the way you act."

Sep 25, 2011
Anytime you want to discuss this Oliver instead of repeat yourself I will stop reporting your posts.

I do identify myself. I sign every set of posts. My online identity is Ethelred, EthLred, or Ethelred Hardrede. I am the person that has been disproving you for two years straight without you being able to show evidence to support yourself. Clearly my skills trump a Phd.

Deal with what I say. Nearly any Crank can tell you that it is the ideas that count. Yours are wrong and it doesn't matter what your credentials are. However I have taken more astronomy than you AND I clearly am far better at discussion than you. You seem to have been unaware of the PEP, the math showing black holes MUST form is there is enough mass, and you didn't even read the letter you posted a link to that was supposed to show perfidy on Kissinger's part.

And that "kind regards' is just as hypocritical as ever. Is that what you said to the children?


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