Solar Flare Interference From 45k Lightyears Away

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. "

Comments

Just to clear something up

[erpbridge]

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

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

Re:Just to clear something up

[saynte]

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

Re:Just to clear something up

[snake_dad]

And, if a person were to get real picky, it happened August 27th, 45,005 years ago :>

Re:Just to clear something up

[jellomizer]

Actually probably more. The flares are from particles that are moving very fast. Close to the speed of light at best. On our sun a solar flare usually takes hours to get to earth while the sun is only 8 light minutes away. So the number is probably closer to 540,000 years ago.

Re:Just to clear something up

[Molina the Bofh]

If you want to get really picky, as we received it in 1998 it would be 540,005 years ago.

Re:Just to clear something up

[Vexalith]

if one assume Warp 9 is possible

That's quite an assumption!

Re:Just to clear something up

[Viadd]

In this case, the ionospheric disturbance was from the X-rays and gamma-rays (high energy photons, travelling at lightspeed) hitting the atmosphere. The main part of the pulse was a huge spike of gamma-rays, followed by bright tail of periodically varying gamma-rays (with the neutron star's ~5 second rotation period) decaying in the next few minutes.

If there were a pulse of sub-light particles coming from the SGR, they would be no longer be a short pulse when they reached Earth fro two reasons: The particles travelling at 90% of lightspeed would come many years before the particles travelling at 89.99% of lightspeed; And the tangled magnetic field of the Galaxy would bend their paths all over the place so they'd be travelling different distances.

Have they got the numbers right ?

[Krapangor]

The energy of a radition source is decreasing with the cubic of the distance as everybody here surely knows. Now taking into account the vast distance a trivial calculations gives a huge amount of energy released at x=0. When you now take Einsteins formula for mass E=m*c^2 you see easily that the released enery equals the adverage mass of 2.3 neutron stars of brightness class M.
I doubt that NASA got their calculations right otherwise we would have 2 large neutron stars (a neutron star and a anti-neutron star) colliding and annihilating here. That's a little unlikely.
Perhaps they tried again to use metric units ;-).

Re:Have they got the numbers right ?

[Anonymous Coward]

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

Re:Have they got the numbers right ?

[Crashmarik]

Square of the distance not cube. Its an inverse square law. Inverse cube is for things like magnetic fields that are generated by dipoles.

So Thats why....

[DigitalReligion]

...I'm getting crappy wifi signals!

45,000 light years away?

[Trigun]

Why didn't we see this coming? Did the scientists need an extra week or something?

Re:45,000 light years away?

[vadim_t]

And how exactly would they see it coming?

Somebody correct me if I'm wrong, but AFAIK it works like this: Something 1 light year away blows up. 1 year later we see it blowing up. We couldn't see it blow up when it actually did, because the light from the event didn't reach us yet!

So, how exactly are going scientists to see that before it reaches us?

Re:45,000 light years away?

[mindstrm]

I think you need to re-evaluate what you think space is made of, and how the speed of light is relevant.

We can't see "ripples" Because they woudl have to move faster than the speed of light to get to us before the event itself did... the maximum speed any effect on the universe from that event moves outwards is the speed of light. Period. Gravitational.. the imaginary "ripples" you think you would see, everything.. NO effects can be detected any faster than that.

In fact, from our perspective, it didn't happen until we see it.

Now, speed of light in a vacuum, yes, is a limit.. what "stuff" do you think it travelled through? Do you think the interstellar dust somehow significantly slowed down the light from the event, yet would allow the effects of that light to ripple towards us faster? Makes no sense.

Re:45,000 light years away?

[Daniel Dvorkin]

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?

Re:45,000 light years away?

[Waffle Iron]

It had a lot of shit to go through in 45,000 years.

Not really. The interstellar medium has about 0.1 atoms per cm^3. This is about 1e20 times less then our atmosphere. 45000 light years is 4.2e22 cm, so it only had to go through the equivalent of 4.2 meters of our atmosphere.

So it's only the same amount of shit as it would encounter on a trip across your living room.

Country??

[FrostedWheat]

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!

Lame joke excuse!

[Gavin Rogers]

So... something new happens that could knock us all offli@%#&$* NO CARRIER

When you are driving home...

[OneOver137]

"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?

Cajun Blackened Astronaut

[Detritus]

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.

Re:Cajun Blackened Astronaut

[gumbi west]

They would have been killed. This is one of the biggest problems for sending people to Mars. If there were such an event durring the mission (which there almost certainly would be durring the two year mission) they would have to be in a well shielded room or would die.

How well shielded? a few meters of water would sufice, but this is getting expensive to send into space. BTW, water would be used because it is the best shield of high energy neutrons which can break up say, lead, into many protons and neutrons each of which could be more dangerous than the original particle.

Presnetly NASA keeps people on call to determine if all astronauts need to come down after each solar flare. This person has 15 minutes to make the call... Talk about stress.

Re:Cajun Blackened Astronaut

[Viadd]

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.

Re:Cajun Blackened Astronaut

[sql*kitten]

How well shielded? a few meters of water would sufice, but this is getting expensive to send into space.

That's a common misconception. In The Case for Mars, Dr Robert Zubrin uses NASA's own data to demonstrate that during a trip to Mars, astronauts would receive about as much radiation as someone who'd lived their life in Colorado. Yes, there is a slightly increased risk of cancer but a) you increase your own risk every time you fly and b) they're flying to Mars - and that's pretty damn risky in and of itself!

This was 5 years ago

[Skapare]

When I saw this story on Slashdot, I was trying to think back to having experienced any radio effects back on 27 August, but I couldn't recall any. Then I read the article and saw that it was really a 1998 event only being written about just now, 5 years later. From an academic study perspective, that's fine. The article is about these effects in general and the study being made of them. The 27 August 1998 event was merely an example of one that played a significant role. And as they report, there have been 10 of these since, and the potential for much larger ones.

Re:Not only that

[Anonymous Coward]

The article talks about two unrelated events about a day apart. The first was from our sun. That was the one which registered the solar protons. The second one was an extrasolar event which did not register any protons.

It's more basic than that.

[mindstrm]

Time, as you know, is all relative.

As there is no absolute time... to say "it blew up but we didnt' see it yet" is actually inaccurate... it didn't blow up as far as we are concerned until we saw it. Before that, the effects of the explosion had no effect on the universe as far as we are concerned.

It's not jjust the light from the event, but the gravitational and other effects as well.. for all intents and purposes, the event doesn't happen until we see it.

Hams were first to notice

[M1FCJ]

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

Solar Flare?

[Xetrov]

How can it be a SOLar flare if it isn't from Sol?

Grr, slashdot is too Sol-centric...

Re:Just goes to show you.

[mskfisher]

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? :)

Re:a stupid pet peeve of mine

[caluml]

Stellar... Reassuringly expensive.

What if ..

[agonz28]

Just wondering ... What if this event had to happen much closer to earth?
say 500 Light years ..
The magnetic storm woud be thousands of times more powerful
How would that affect life here on earth...