Massive Black Hole Devours Star 77
H3xx writes "Astronomers have observed a black hole shredding a star and sending a powerful beam of energy toward Earth. When it was first observed on March 28th by the Swift spacecraft, it was thought to be the implosion of an aging star, but is now believed to be the result of a star wandering too close to a black hole, imploding and converting 10% of the star's mass into gamma radiation. The energy burst is still visible by telescope more than two-and-a-half months later, the researchers report in the journal Science."
Re:"beams" of energy (Score:5, Informative)
generally black holes eject along beams from their poles. if one of those beams is pointing towards earth we get a big flash; if it's not we don't see as much.
it's much the same with pulsars. the standard model is that they're neutron stars emitting extremely focused radiation from their poles.
Re:Naaaa. not gonn happen like this (Score:5, Informative)
I'm sure the people spending years programming supercomputers to model supernovae will be fascinated to hear your ruminations. Not sure they'd agree with them, though...
Just a few thoughts in reply:
Not every star goes supernova. In fact, supernovae are really very rare. Most stars have a less violent end. Our own sun, for example, is never going to go supernova but is likely to become a planetary nebula and look quite beautiful to a civilisation a few tens of light years away.
Even if this star would be massive enough to go supernova, why would you assume that tidal stresses would cause a supernova? Or that you can trigger a supernova like that? Supernovae happen when the core of the star is basically made out of iron and it stops burning; the envelope then collapses under gravity and bounces, dramatically and catastrophically. A star that isn't at that stage isn't going to go supernova regardless of what stresses you put it through.
A supernova spits out a lot of gamma radiation, that's true. It also spits out a hell of a lot of other radiation -- and it's pretty characteristic, too. We know what the spectra of different types of supernovae look like and we know how the light-curves evolve over time. If this was a star going supernova we could tell, even if it were falling into a black hole at the same time.
And theoretically, it's possible for a star to become elongated and stretched. Consider a much less brutal example -- a red giant being orbited by a smaller orange star. There's something called a "Roche lobe" which is basically defines where the star's gravity dominates. That means that something within the Roche lobe of one star it's bound to that one, while if it's within the Roche lobe of the other it's bound to *that* one. But if the stars get close enough, there's a point where the Roche lobes meet -- and the two lobes elongate to touch one-another. The giant can then expand, as giants are wont to, and fill its Roche lobe. It takes on an elongated form (and a small stream of matter spirals into the other star). A slightly more dramatic version of this is when a star is orbiting a neutron star; given enough material flowing from the elongated companion onto the neutron star and you *do* trigger a supernova... but it's of the neutron star and not the companion.