There is speculation as to the nature of the stellar collapse.
Yes. We don't know for certain yet whether Betelgeuse has entered an irreversible collapse, or whether the alleged Mauna Kea contact misunderstood what he saw. I've been continuing to watch the scientific news sources and I've yet to see anything confirmed beyond the continuous shrinkage from 1993 to 2009.
There is complacency in that the big gun is aimed away from the earth...what percentage of the total radiation is emitted at other angles from the poles?
It's not complacency. We're sure enough of Betelgeuse's orientation that we can say with good confidence that its poles are aimed about 80 degrees away from us, which would put us well out of the way of a GRB. (Not that we're 100% certain what the mechanism of a GRB is yet, but according to the best working theories, GRBs are a highly directional polar event associated with only extremely violent events.) The rest of the energy emission from such an event would be no threat to us at our 500-600LY distance; yes, a Type II supernova of Betelgeuse would be an extremely violent event, but it's still subject to the inverse-square law. If we were only a few light-years away, or if we were, say, 50LY away and in line with one of the poles, we'd have cause to worry. From here, it'll be a spectacular show, but we can categorically say that we'll be in no danger from it.
What confidence level do you have that the previously observed data will bound this event?
Well, that depends how you mean the question. This is an extremely large and massive star, and is likely to be one of the more energetic supernovae ever observed when it finally does go. But it's not going to be the six orders of magnitude more violent than any previously known supernova that would be necessary for it to threaten us. As previously stated, the original doomers.us article grossly overstates the possible intensity of the event.
From what I am reading, the facts seem to be that a very nearby star is shrinking at an accelerating rate and becoming oblate.
Well, "very nearby" is a relative thing. Barnard's star is very nearby in stellar terms, at 6LY. So is Proxima Centauri at 4.2LY, and Wolf 359 at just under 7.8LY and Lalande 21159 at around 8.3LY should probably qualify too. They're just down the street. By the time you get out to 14, 15, 16LY, there's quite a few stars out there and you're wandering over to the next block. By comparison, at over 500LY, never mind the stellar neighborhood, Betelgeuse isn't even in town. It's somewhere over in the next county.
Re: Quantification
It's not complacency. We're sure enough of Betelgeuse's orientation that we can say with good confidence that its poles are aimed about 80 degrees away from us, which would put us well out of the way of a GRB. (Not that we're 100% certain what the mechanism of a GRB is yet, but according to the best working theories, GRBs are a highly directional polar event associated with only extremely violent events.) The rest of the energy emission from such an event would be no threat to us at our 500-600LY distance; yes, a Type II supernova of Betelgeuse would be an extremely violent event, but it's still subject to the inverse-square law. If we were only a few light-years away, or if we were, say, 50LY away and in line with one of the poles, we'd have cause to worry. From here, it'll be a spectacular show, but we can categorically say that we'll be in no danger from it.
Well, that depends how you mean the question. This is an extremely large and massive star, and is likely to be one of the more energetic supernovae ever observed when it finally does go. But it's not going to be the six orders of magnitude more violent than any previously known supernova that would be necessary for it to threaten us. As previously stated, the original doomers.us article grossly overstates the possible intensity of the event.
Well, "very nearby" is a relative thing. Barnard's star is very nearby in stellar terms, at 6LY. So is Proxima Centauri at 4.2LY, and Wolf 359 at just under 7.8LY and Lalande 21159 at around 8.3LY should probably qualify too. They're just down the street. By the time you get out to 14, 15, 16LY, there's quite a few stars out there and you're wandering over to the next block. By comparison, at over 500LY, never mind the stellar neighborhood, Betelgeuse isn't even in town. It's somewhere over in the next county.