Betelgeuse is a red giant, about 600 light years far from Earth, and ... it's dieing. That star is running out of helium and soon [thousands, millions of years?] it will explode in a supernova. That day, if humans will still be here, we will see two suns in the sky [actually not exactly to suns, but our sun plus a strong point of light, visible also during day light]. I remember that in 2012 there was who said that Betelgeus had exploded and that it will take 600 years to see it in the sky [it's true, the light of an eventual explosion of supernova would get 600 years to reach our solar system]. The problem is that with the light of the explosion, also the radiations would come ... 600 light years is not a so great distance for the energy of a supernova. http://www.nasa.gov/mission_pages/herschel/multimedia/pia16680.html http://www.nasa.gov/mission_pages/herschel/news/herschel20130122.html
Yes, it was, regarding in particular the reference to Betelgeus, I think it's a modern interpretation. In 2012 there were all the possible [and impossible!] prediction about the end of the world ...
Yeah it is. If you're talking light energy, the intensity (energy per unit area) is inversely proportional to the distance. 600 light years is pretty far. My guess is a super nova 600 light years away produces a lot less energy that reaches Earth than a star right next door at 0.000016 light years away.
When you deal with a supernova you have to consider the brief emissions of gamma radiations in the most energetic phase of the explosion ... Studies have suggested that the critical distance for these kind of radiations would be just of about 600 light years. There is even who connects some events of mass extinctions on our planet with the gamma emissions of supernovae in the nearby of our solar system.
The gamma ray bursts are directional, blasting out the north and south poles of the star. Those poles aren't pointed near earth, so it's not a danger. The particle wave coming out would be a danger, but that would be traveling well below lightspeed, and would take 100,000 years to reach earth. I assume by that time humanity will either be gone or able to adapt.
There's a star that looks like a candidate for a GRB and it's about 8000 light years away. At that distance if the poles were pointing at the Earth we'd be in trouble.
That would be WR 104. Fortunately for us, further observation indicates WR 104 is pointed around 30 - 35 degrees away from earth, leaving us out of the firing line. http://news.discovery.com/space/history-of-space/gamma-ray-wolf-rayet.htm
This is just my gut, I have no rational basis to back this up, but I think it already has and we just don't know it.
Betelgeuse will explode after the moment that star starts forming iron elements in its core. Iron is poison to stars.
We see that star with a delay of centuries, so it's possible it has already happened. Simply it will be a show that our descendents will admire in the sky, not we and not now.
We've all got to go sometime - killed by radiation from a supernova is a pretty cool way to die. I'm game.
Yes, and it's not about a common star, it's a red giant with more than 15 solar masses, this means that after the explosion a neutron star will survive for a while, before that the collapse will go on generating a black hole.
Personally I'm a big fan of someone genetically modifying a tree which produces mustard gas instead of oxygen, then this tree taking over the world and us all slowly dying from our lungs filling with sulfur. But death by black hole will suffice.
well, with a bit of patience we could observe something better: in some millions of years our galaxy will crash against Andromeda. That will be a show, the crash of two galaxies, one into the other.
My understanding is that the only thing that would cause might be a really spectacular night sky. Even in galaxies stars are so far from each other other that the chances of a collision are effectively nil. Of course, by that time I think our own sun will have exploded like Betelgeuse
Is that even possible? Where would it get the sulfur from? It's not everywhere, to my knowledge not in all soils.
Astronomers have done simulations of collisions of galaxies [making literally astronomical calculations, simulating the interaction of billions of stars with supercomputers]. Now, the low density of stars in the galaxies says that you are right, in the first phase. The problem comes for the stars near to the centers of the systems. The interactions between the two super black holes would generate gravitational waves causing deep distortions in the space times with the possibility that thousands of stars could be ejected at relativist velocity to the outer space. But we do doubt that around the stars near to the center of a galaxy there are planets with life on.
