Slashdot Mirror

← Back to Stories (view on slashdot.org)

Solar Flare Interference From 45k Lightyears Away

Posted by CmdrTaco on from the duck-the-flares-are-coming dept.

Wan2Be writes "Nasa has a story about a solar flare on Aug. 27 that affected our planet with radio bounces and blackouts - but it wasn't from old Sol, it was from SGR 1900+14, a neutron star about 45,000 light years away. "

10 of 154 comments (clear)

  1. Just to clear something up by erpbridge · · Score: 5, Insightful

    Slight misconception from the summary. The event happened on August 27.

    But that was August 27, 1998. Not just a couple weeks ago.

    1. Re:Just to clear something up by saynte · · Score: 5, Funny

      Actually, if a person were to get picky, it happened August 27th, 45,000 years ago :D

  2. Country?? by FrostedWheat · · Score: 5, Funny

    The station faded--a blackout--and was moments later replaced by country music

    The universe has a sick sence of humour! High-energy solar flares are one thing, but country music? That's just cruel!

  3. When you are driving home... by OneOver137 · · Score: 5, Funny

    "in the middle of the night and, unexpectedly, a country tune blares out of your radio, you might wonder ... did a magnetar do that?" Or do you just have poor taste in music?

  4. Re:Have they got the numbers right ? by Anonymous Coward · · Score: 4, Informative

    Actually, since we are talking about electromagnetic radiation, the energy will drop with the sqaure of the distance, not the cube. This might impact your calculations just a little bit.

    - GK

  5. Cajun Blackened Astronaut by Detritus · · Score: 4, Interesting
    What sort of radiation dose would an astronaut receive if he was located outside the Van Allen Belt?

    Solar flares were a serious concern to the Apollo astronauts, who were at risk while traveling to the Moon.

    --
    Mea navis aericumbens anguillis abundat
    1. Re:Cajun Blackened Astronaut by Viadd · · Score: 4, Informative
      What sort of radiation dose would an astronaut receive if he was located outside the Van Allen Belt?
      I worked it out once. This particular SGR burst would have given an astronaut the equivalent of a dental X-ray. Pretty potent for half-way across the Galaxy, but not a health hazard. And the Van Allen Belts wouldn't have provided any shielding because the X-rays/gamma-rays are uncharged photons, which aren't affected by Earth's magnetosphere.

      Solar flares are most deadly because of the proton flux, which would be blocked, but which travels much slower than lightspeed. If you see X-rays from a solar flare, it tells you that you have an hour or so to get into a shielded environment before the big storm hits.

  6. Hams were first to notice by M1FCJ · · Score: 4, Insightful

    Isn't it interesting that radio amateurs were one of the first groups noticed there was something strange going on?

  7. Re:45,000 light years away? by Daniel+Dvorkin · · Score: 4, Insightful

    It can't.

    The fastest way for any information to travel (again, as far as we know) is as light. Period. So if the event that's happening is a propagating wavefront of light, nothing is going to get to us before the light itself. ("Light" here including other parts of the EM spectrum: radio, X-rays, whatever.)

    Let's suppose that at the halfway point, ~22,500 LY away, the wavefront had some effect -- say, it hit a cloud of interstellar gas and caused that gas to fluoresce. Would we see that fluorescence? Maybe -- except while the light from that fluorescence is traveling toward us, so is the light from the original event. The light from the secondary events can't move any faster.

    Okay, here's a terrestrial analogy. Let's suppose someone telephones me and says, "By the way, while I've got you on the line, I'm also calling Trigun on another phone." Now let's suppose I want to call you and warn you about this incoming call. (Maybe it's a bill collector.) No matter how quickly I try to call you, it doesn't matter, because the other guy has already placed the call. Does that make sense?

    --
    The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
  8. Re:Just goes to show you. by mskfisher · · Score: 4, Interesting
    You've got that right.
    If you're impressed by how these "magnetars" can affect us, check out gamma-ray bursters.

    From http://www-2.cs.cmu.edu/afs/cs.cmu.edu/user/mnr/st /std086:
    The integrated flux of the strongest burst, GB790305, was 10^-4 ergs/cm^2 (the time structure of this pulse was consistent with a
    rotating or precessing neutron star; the period is about 8 seconds).
    A lethal dose to unshielded astronauts would be about 4 x 10^6 ergs/cm^2, so anyone 200,000 closer to the burster than we were had
    better have good shielding.

    ...

    If the burster was at 5 billion light years (say), the lethal radius for unshielded astronauts would be around 25,000 light years. I hope one doesn't go off in our galaxy soon.
    We might get beat up real good by one of those bad boys - the Earth could get cooked if one happened right outside our neighborhood.
    Ah well, what's life without a little excitement? :)
    --
    0x0D 0x0A