The Sun unleashes an X5.4 class flare

By Phil Plait | March 6, 2012 9:15 pm

Around midnight UTC last night, Active Region 1429 on the Sun exploded with a fairly large flare: rated at class X5.4, it was among the largest seen in the current cycle.

Video of the flare has been created using images from the Solar Dynamics Observatory:

Yowza. This flare was big enough that it may cause some communication issues and will probably lead to some nice aurorae, but otherwise is no danger to us here on Earth. I haven’t heard much else, but I’ll update this as I do.

Tip o’ the SPF 5000 to Camilla Corona SDO.

Related Posts:

NASA’s guide to solar flares
Another big solar flare
Awesome X2-class solar flare caught by SDO
The Sun’s still blasting out flares… BIG ones

MORE ABOUT: SDO, solar flare

Comments (13)

  1. David

    Does the Sun need some prozac?

  2. Wzrd1

    I’m on the space weather mailing list, old news now for me.
    Along with a CME and an edge effect of one tomorrow AND some interaction effects at the same time.
    Not that it’d knock out anything more important than a glowworm…
    But, SOME might get a good light show this week!

  3. John Paradox

    David Says:
    March 6th, 2012 at 9:36 pm

    Does the Sun need some prozac?

    Preparation H?


  4. Pete UK

    The BBC screened a fairly good edition of their science vehicle Horizon yesterday – all about solar flares and CMEs, how they pose a threat to our electronics-based world and what we are starting to do to mitigate the risk. A tad sensationalist, but good for all that.

    Available on BBC iPlayer, for those who can access that content, at

    On a related subject, the first of another great documentary series from the Beeb which started last weekend:

    Orbit: Earth’s Extraodinary Journey.

    This was excellent. Truly, our cup runneth over.

  5. Very cool stuff.

    Speaking of cool stuff in the solar system, Dr. Plait, could you discuss the “Hot Flow Anomaly”? I think that would be a terrific blog subject.

  6. Messier Tidy Upper

    @ ^ Larian LeQuella : I’m not sure that “cool” is right word here somehow! 😉

    Is it just me or perhaps the angle we’re veiwing it from or did this flare seem set a quarter or so of our Sun quivering? Great clip. 8)

    Wonder if the helioseismologists noticed a sunquake as a result of this and if so what the solar Richter scale equivalent would be?

  7. Carey

    I love that little “after-burp” that pushes out from the sunspot at about a 5 o’clock angle after the main blast.

  8. Chris

    @5 Messier
    The satellite’s camera is shortening the exposure to keep the flare from being over exposed. This reduces the intensity of the rest of the sun producing the quivering I believe you are referring to.

  9. Hot off the presses (or at least the SWPC alerts mailing list):
    Space Weather Message Code: ALTPX3
    Serial Number: 25
    Issue Time: 2012 Mar 07 1417 UTC

    ALERT: Proton Event 10MeV Integral Flux exceeded 1000pfu
    Begin Time: 2012 Mar 07 1410 UTC
    NOAA Scale: S3 – Strong

    NOAA Space Weather Scale descriptions can be found at

    Potential Impacts: Radiation – Passengers and crew in high latitude, high altitude flights may experience increasing radiation exposures. Astronauts on EVA (extra-vehicular activity) are exposed to elevated radiation levels.
    Spacecraft – Single-event upsets to satellite operations, noise in imaging systems, and slight reduction of efficiency in solar panels are likely.
    Radio – Degraded or episodically blacked-out polar HF (high frequency) radio propagation.

  10. Mark

    It looks like the whole surface of the sun moves following the flare. Is this akin to an explosion followed by a concussion wave here on earth?

  11. Messier Tidy Upper

    @8. Chris wrote :

    @5 Messier – The satellite’s camera is shortening the exposure to keep the flare from being over exposed. This reduces the intensity of the rest of the sun producing the quivering I believe you are referring to.

    Ah, that makes sense – Thanks. :-)

  12. Jim Mooney

    There are some studies linking geomagnetic storms with negative physiological and psychological effects, so we’ll see if there are any artifacts of that, although adnittedly statistically anomalous, tomorrow.


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