SoylentNews is people
SoylentNews
A billion light years away, a monster star tore itself to shreds.
And by that I mean it tore itself to shreds. In general exploding stars — supernovae — leave behind a neutron star or black hole, but in this case it’s possible that the explosions was so over-the-top ridiculously violent that even the star’s core was ripped apart. It’s difficult to exaggerate how violent an event this was… but then, when huge amounts of antimatter are involved, that’s what happens.
Yes, seriously.
The event is called SN2016iet, a supernova that was detected on November 14, 2016. It was first spotted in data taken by the space-based Gaia observatory, and was followed-up by the Catalina Real-Time Transient Survey, then Pan-STARRS, and eventually the huge Gemini Telescope to get deep spectra of it. But it didn’t take long to determine that this particular supernova was weird.
And then they found it was really weird.
But even then it didn’t behave properly. Instead of fading away into obscurity, the supernova continued to shine, fading much more slowly than usual. The astronomers were still able to observe it in spring of this year, more than two years after the initial explosion.
[...] So in the end, nothing with this supernova fits. No one model seems to explain everything it’s doing, which means it truly is one of a kind. Nothing like it has ever been seen before, and we can’t fully explain its behavior.
I wonder though, just how long this will remain a unique event. We now observe thousands of supernovae every year. Even if this event is extremely rare, we’re likely to find another one eventually. Maybe not exactly like it, but close enough that we can compare them, see how they differ. That will help astronomers understand how these catastrophic events occur in the first place. Although these kinds of supernovae are at the tippy-top of the scale, they provide checks on our understanding of the physics of exploding stars under extraordinarily extreme conditions.
And, as I mentioned before the very first stars in the Universe may have exploded like SN2016iet, so observing it is like a window in to the very distant past, 12 billion or more years ago, when the very first generation of stars existed. For that reason alone, I hope we find lots more just like it.
(Score: 0) by Anonymous Coward on Sunday August 18 2019, @09:31PM (2 children)
Here is what they do:
MOND predicts very precisely what observations should be observed, but there is uncertainty in some of the measurements. So they use statistics saying that "if MOND is correct, we should only reject that model 5% of the time". Then they look at 100 galaxies, and see that, according to their criteria, MOND is not consistent with the data for 3 of them. Then they say, see we need dark matter to explain everything.
Using their methods, if MOND is 100% accurate, we would expect 5% of the galaxies to be inconsistent with the observations. In reality, it is even less than that.
So any theory that cannot explain MOND (ie, GR + dark matter) is worthless.
(Score: 0) by Anonymous Coward on Monday August 19 2019, @05:54PM (1 child)
Rigorous bounds on the quality of the approximation derived from the laws it approximates a la deriving a probabilistic version of Boyle's law from more fundamental laws, or measurement error?
If the measurement error, it's silly to look for better models.
If the former, it's worth looking for them.
Presumably physicists wouldn't make such a simple mistake, and it's not likely to be measurement error.
(Score: 0) by Anonymous Coward on Monday August 19 2019, @07:17PM
This is statistical error, they assume the brightness, etc that is directly measured is not exactly correct but instead sampled from a distribution (eg, normal distribution). I think you'll just have to look up how confidence intervals work because I can tell you are unfamiliar with the topic.