Another big solar flare

By Phil Plait | August 9, 2011 10:32 am

At 03:48 UT on August 9 (earlier today as I write this), the Sun blasted out another flare, the largest of the cycle so far. It was seen by the orbiting Solar Dynamics Observatory:

[Click to ensolarnate.]

This image shows the Sun in the far ultraviolet; sunspots appear bright at this wavelength and the flare is pretty obvious! It came from a sunspot that is near the Sun’s limb. Since it was so far to the side it’s unlikely to do us much harm here on the Earth’s surface, though there may be some satellite communication issues. It also blew out a storm of subatomic particles, which might potentially harm astronauts in space. I haven’t heard yet if the crew on the space station will need to seek shelter deeper inside the structure (they’ve had to do that before in solar events, but there’s never been any case of diagnosed harm).

SDO also captured pretty dramatic video of the event:

This was an X6.9 flare, which is pretty big, but still not like the ones we saw in late 2003 which were far more powerful. Still, this is the biggest flare from the new solar cycle, and I think the first flare from this particular sunspot, named Active Region 1263. Last week, AR 126a blew out several flares, but none as big as this one.

By coincidence I was at Big Bear Solar Observatory in California just two days ago, and saw AR 1263 roiling on the Sun’s surface. 1261 was already about to slip behind to the far side of the Sun, and I didn’t think much of 1263 because it was near the edge as well. It goes to show you that with our nearest star, it’s best to expect the unexpected!

… and the astronomers with whom I talked were keeping their eyes on several other spots on the Sun as well. The new solar cycle is ramping up, so one thing I can say with some certainty is that we’ll see more and more powerful flares as time goes on.

[Updated to add: I originally wrote that this was an M6.9 flare, when it is in fact an X6.9 flare, which is ten times more powerful, and the biggest so far in years. To avoid confusion, I simply corrected the mistake in the post. My apologies.]

Credit: NASA/SDO/

Related posts:

Sun blows out another big one; expect aurorae tonight
The Sun lets out a brief flare
The Sun lets loose a huge explosion
INCREDIBLE solar flare video

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures
MORE ABOUT: flare, SDO, Sun

Comments (23)

  1. QuietDesperation

    The sun is trying to kill us!!!!


  2. Messier Tidy Upper

    Blue Sun!
    So B-star blue a shade! 😮
    I’m glad our Sun is G,
    Gee, so warm already
    If azure, too hot we’d be! 😉

    Yeah, I know its a false colour image, but, wow, that fires the imagination and looks (ironically – if that’s not misusing that word) so cool. 8)

    Thinks of all the blue dwarfs (eg. Regulus), giants (Alpha Crucis) and supergiants (Rigel) speckling our sky yet so rare really, wonders if they look anything like that. Most of them of course are rotating so much much faster and have different internal structures. (Convection and radiation layers reversed for instance.) Hmm.. Approaching B stars with their extreme luminosity and mass would be .. challenging .. to say the least, too methinks!

  3. Carey

    “My eyes!” –SDO

  4. Michael

    Well, sorry Phil, but here’s a slightly more detailed analysis:,21088/

    I think we can trust the experts on this 😉

  5. Allen Thomson

    The straight lines radiating out from the flare are sensor artifacts, no?

  6. bystander

    “Last week, AR 126a blew out several flares”

    Shouldn’t that be AR 1261?

  7. Doug Little

    The sun is gearing up for 2012? The end is nigh!

  8. See the Aesop Institute website for some maps worth a thousand words regarding a little known nuclear threat that can result from the four extreme geomagnetic storms the NOAA forecasts during the next 3 to 5 years. The peak threat will be in 2013.

    Ironically, wise 24/7 action can unite the nation, revitalize the economy and generate jobs.

  9. Wzrd1

    From NOAA:
    :Product: Report of Solar-Geophysical Activity
    :Issued: 2011 Aug 09 2200 UTC
    # Prepared jointly by the U.S. Dept. of Commerce, NOAA,
    # Space Weather Prediction Center and the U.S. Air Force.
    Joint USAF/NOAA Report of Solar and Geophysical Activity
    SDF Number 221 Issued at 2200Z on 09 Aug 2011
    IA. Analysis of Solar Active Regions and Activity from 08/2100Z
    to 09/2100Z: Solar activity was high. Region 1263 (N17W83) produced
    an X6/2b flare at 09/0805Z, the largest x-ray event so far in Cycle
    24. This flare was accompanied by multi-frequency radio emissions,
    including a Tenflare (710sfu), and Type II (1551 km/s) and IV
    signatures. A full halo CME was subsequently observed in LASCO C3
    imagery at 09/0906Z. Initial plane-of-sky speed was estimated to be
    about 1000 km/s. Earlier in the period, a CME was observed in LASCO
    C3 imagery at 0406Z. This event was attributed to an M2/1b flare
    from Region 1263 at 09/03435Z. While the area of Region 1263
    diminished over the last 24 hours, the longitudinal extent expanded,
    and the region ended the period as an Ehc type spot group with a
    beta-gamma-delta magnetic configuration.
    IB. Solar Activity Forecast: Solar activity is likely to be low to
    moderate. A slight chance for an isolated X-class flare, and/or
    proton event, remains for Day 1 (10 August). Event probabilities are
    expected to gradually decrease as Region 1263 rotates around the
    west limb.
    IIA. Geophysical Activity Summary 08/2100Z to 09/2100Z:
    The geomagnetic field was quiet to unsettled through the period under
    the continued influence of a coronal hole high speed stream. Solar
    wind speed at the ACE spacecraft was approximately 600 km/s for most
    of the period. The Bz component of the interplanetary magnetic
    field was predominantly near zero. The greater than 100 MeV protons
    crossed the 1 pfu event threshold at 09/0825Z, reached a maximum of
    2 pfu at 09/0855Z, and ended at 09/1045Z. The greater than 10 MeV
    protons crossed the 10 pfu event threshold at 09/0845Z, reached a
    maximum of 26 pfu at 09/1210Z, and ended at 09/1715Z. The greater
    than 2 MeV electron flux at geosynchronous orbit reached high levels
    during the period.
    IIB. Geophysical Activity Forecast: The geomagnetic field is
    expected to be predominantly quiet to unsettled for the next three
    days (10-12 August). Unsettled conditions are expected on Day 1 (10
    August) as a weak remnant of the 08 August CME arrives. Currently,
    a return to mostly quiet conditions is expected on Days 2 and 3
    (11-12 August). Analysis of the 09/0906Z CME is presently underway
    to determine its potential geoeffectiveness.
    III. Event Probabilities 10 Aug-12 Aug
    Class M 60/40/20
    Class X 10/10/05
    Proton 99/60/10
    PCAF Yellow
    IV. Penticton 10.7 cm Flux
    Observed 09 Aug 098
    Predicted 10 Aug-12 Aug 095/085/085
    90 Day Mean 09 Aug 096
    V. Geomagnetic A Indices
    Observed Afr/Ap 08 Aug 008/010
    Estimated Afr/Ap 09 Aug 008/008
    Predicted Afr/Ap 10 Aug-12 Aug 010/010-007/007-005/005
    VI. Geomagnetic Activity Probabilities 10 Aug-12 Aug
    A. Middle Latitudes
    Active 20/15/05
    Minor storm 05/05/05
    Major-severe storm 01/01/01
    B. High Latitudes
    Active 15/20/10
    Minor storm 10/05/05
    Major-severe storm 05/05/01

    I’m thinking it’ll be interesting for those who handle long distance electrical power, but not overly so and MORE interesting to satellite folks and the ISS crew.
    But, thank the inverse square law for distance effects. 😉

  10. It’s ramping up for 2012! Heid in teh ziggurat bunkerz!

  11. jearley

    What? We can not forecast storms with any accuracy at all. We can state only generalities, such as ‘The Sun will be more active next year’ Which is equivalent to stating that it will be colder next winter. There is NO prediction that ANY Solar storms will hit the Earth next year, nor the year after.
    Which is not to say that it could not happen, and we should prepare for it with plans to shut down some of the EHV transmission lines. Doomsaying about the upcoming solar max is not useful. Predicting specific solar activity more than a few days in advance, when we know that a CME is on the way, is nonsense.

  12. Joseph G

    Wow! As someone mentioned above, there’s a sizable image artifact there, which seems to be centered on the brightest part of the flare. Is this a result of CCD pixels “overflowing”?
    If so, it kinda gives you pause at the power involved – I mean, that’s a solar flare too bright for a machine that was designed to stare at the sun.

  13. Joseph G

    Wzrd1: I love how it’s structured exactly like a terrestrial METAR forecast. Makes me feel like I’m living in the future.

    “Good morning, Luna City! It’s 05:32 GMT – first, let’s get right to Meteobot7000 for the weather today – how goes, MB?”
    “Fantastic, Tom, thanks! As for the commute, things could be better – we have a light solar plasma persisting into the evening, and a 30% chance of protons, so expect lots of shuttle delays, and don’t forget to pack your lead-lined jumpsuit!”

  14. JimR

    This flare may not effect the earth, but it is going to be terrible for the twin earths
    coming into view soon just in time for their debut in the movies about them.

  15. Robin


    I see you like to instill fear. That’s very smart. After all, it is all the rage in political circles, and your website reads like political propaganda. In fact, your site reads a lot like anti-vaccine sites, intelligent design sites, Chemtrails sites, sites predicting cataclysm from HAARP, and so on. That is to say that your site has a paucity of facts supporting your claims and dangerous warnings.

    Zero point energy? Really? Can you analytically show how zero point energy would be extracted? It would be terribly interesting to see how energy would be extracted from a field or quantum system when either is at its lowest possible energy state.

  16. DrFlimmer

    @ #5 Allen Thomson + #14 Joseph G

    Yes, these rays are artefacts of the camera. It is designed to stare constantly at the sun, but if this piece of plasma brightens suddenly in one spot it causes the pixels to overflow. Think of it as if you would stare at a light bulb which suddenly becomes several factors brighter. You would be dazzled as well, don’t you think? 😉

  17. Cometkazie

    I notice on another site of the flare in 308A that a phenomenon like a shock wave emanates but seems to go only in one direction, to the SW, assuming N is up in the image.

    I believe this phenomenon has been discussed here and has a name, but why doesn’t it go out in all directions like the ripples from a rock thrown into water?


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