Poof.
It will apply directly to our foreheads.
Just to increase the tension, here’s the Gamma-ray Burst Real-time Sky Map.
There’ve been four sighted in the last week alone.
I’m sorry, fight my ignorance for me.
Does the earth get vaporized or something? Can a supernova from across the universe cause this, or only within a certain proximate range?
Wikipedia is not helping much here :smack:
No one is sure how far away you need to be for safety, but statements like this are common:
Some astronomers claim that even 90,000 light years, across the galaxy, might be too close for comfort. I suppose it depends on the size of the burst.
No one worries much about gamma ray bursts that originate in other galaxies.
Of course, there’s not much point in worrying about a nearby burst either.
I wouldn’t worry too much. It has to happen fairly close to us (in cosmic terms, at least)–say, several hundred to a few thousand light years, and one of the axes of rotation of the star must be pointed more or less directly at us. Simplistically stated, the intense magnetic field that is created during a supernova essentially funnels electrically charged material towards the poles, resulting in twin jets of gamma rays radiating along the axis of rotation. Clearly, however, there is considerable beam spread since we observe many of these GRBs each year with no ill effects; we would not be able to observe them unless they were pointed in our general direction. But, if one were close enough, and was aimed our way, yeah, we’d be toast. The atmosphere would be blown away, the oceans would boil off and everything on the surface of the Earth would be instantaneously charred. There’s just that much energy in a GRB.
So THAT’S what happened to the martians…
:eek:
Thank you!
I get a figure of about 17.4 million kilograms, assuming that the entire mass of Betelguese was thrown off in a uniform spherical shell. This actually isn’t too far off of some estimates I’ve seen of the yearly meteorite mass gained by the Earth each year, although of course it’s still a tiny fraction of the entire mass of the Earth.
They’d be moving at something like (1-10[sup]-16[/sup])c, or for the fun of it: 0.9999999999999999c. Indeed, the light hasn’t got a snowball’s chance of catching up for any supernova we could see.
What are the odds of this happening? I guess the closer to Earth, the better the chances, but, say for a star 500 light years away, for all the possible allignments of it’s pole, what % of them would put the burst on a course to hit Earth?
(I’m not sure how hard of a problem this is to figure out, I’m sure it requires knowing arc’s and radians and whatnot. And you’d need to know how much the pulse dissipates outward from the line over time, and how close to the actual plumb line of the pulse the Earth needs to be to be effected from that distance)
Did you ever think of contributing horoscopes to The Onion 
Nope, when I was in astronomy, I was a planets person. Some of my information might be a bit out of date, too- I haven’t been keeping up with the latest in the field since I left in 2000.
There is a theory that that’s what happened to cause the mass extinction at the end of the Ordovician period, one of the worst mass extinctions in Earth’s history.
One gamma-ray burst can ruin your whole day.
These astronomers seem to think it’s not very likely that a gamma ray burst will get us. Seems that our galaxy isn’t optimal for producing gamma ray bursts. It’s not impossible, but not terribly likely, either.
If any of you are fans of the History Channel show Mega Disasters, they had a show about what might happen if a gamma ray burst (one not close enough to wipe out all life on Earth) hit us.
For stuff like this, you need to go to the How To Destroy The Earth page.
According to Steve Thorsett, quoted on that site (and from whom I took a class in grad school at UC Santa Cruz, but not one about gamma ray bursts), no, it won’t vaporize the Earth. Wipe out all life on Earth, maybe, but not vaporize it.
Betelgeuse may not be big enough to create a gamma ray burst when it does go supernova. According to current thinking, you need a supernova that is big enough to produce a black hole. Not all supernovae do this- some leave neutron stars as a remnant. We’re not sure just how big a star has to be to produce a black hole, but we think it has to be at least 20 times the mass of the sun. We think Betelgeuse is only 14 times the mass of the sun (though determining the mass of a star that isn’t a binary is, like determining distances to stars, a tricky business).
I’ve also seen estimates that, according to our currently accepted model of gamma ray bursts from supernovae, a star has to be extremely massive- 40 times the mass of the sun or more- to produce a gamma ray burst. There are stars that massive out there, but they’re extremely rare. Stars as large as our Sun are relatively rare, too, for that matter- something like 80% of the stars in our galaxy are red dwarfs, which are smaller than the Sun.
IIRC, the binary system IK Pegasi is the nearest supernova risk at ~150 LY. It’s a type 1A candidate, which means that almost all of its mass (~2.8 solar masses) would be ejected by the explosion.
I’ll get you for this. I don’t know how or when, but I’ll get you.
RR
Is this a Hulk reference? I don’t remember the name of the character that got smarter instead of stronger, but reading your post makes me think of him.
Was it refering to something else?
There’s a product called head on for headaches. It’s a stick of… something (reminds me of oversized chapstick)…
The commercial says “head on, apply directly to forehead. Head on, apply directly where it hurts” etc etc. He was making a joke since the quote said “head on” in it.
But AIUI, it won’t be a type Ia supernova risk until IK Pegasi A evolves off the Main Sequence. It hasn’t done that yet.
Even when it does, the red giant will have to be close enough to the white dwarf that the white dwarf can suck material out of the red giant’s atmosphere. Sirius A and B may be too far apart for that to happen (I had read an article, years ago, saying that Sirius B would probably eventually produce a type Ia supernova, but now that I think about it, it makes sense that it wouldn’t- Sirius B is in an orbit with a 50-year period, which clearly isn’t that close to Sirius A). The white dwarf in the IK Pegasi system is much closer to the other star- its orbital period is 21.7 days. So it probably is a more plausible type Ia supernova candidate than Sirius B.
The Leader buys it by the case.
http://www.leaderslair.com/