Boffins baffled as supergiant star just vanishes – either it partially blew itself apart or quietly turned into a black hole Astronomers are on the hunt for a rare gigantic star located 75 million light years away that seems to have disappeared after nearly 20 years of observations. Scientists, led by Trinity College in Dublin, Ireland, wanted to find out what happens during the final evolution stages of massive stars. They settled on what they …
Nah, somebody forget to pay the rent and the power was turned off. Or, the inhabitants of that galaxy's corner were tired of the prying eyes and pulled the curtains.
Surely, an (any) alien explanation is more plausible than the obvious. The question is, when will we pull the curtains? All those eyes looking down on us. Have those aliens no respect for privacy?
That's the same as the 'dust' scenario. If it's happened, you still see it, just in IR, so they're planning to look in IR I think. If it's done the direct-collapse thing then there won't be IR as the resulting object is not luminous, unless it starts accreting crud, when it would be very luminous, but not in IR.
I bet everyone is hoping they've seen a direct collapse!
(I think I am using 'direct collapse' wrong here: that's collapse to BH without a star, but I haven't time to edit it.)
That's the same as the 'dust' scenario. If it's happened, you still see it, just in IR
That assumes that all the energy captured by the Dyson sphere is ultimately used within the Dyson sphere, ending up as heat. However if for example you built the Dyson sphere in order to create Kugelblitzes* to power interstellar craft, then most of the energy would ultimately leave the sphere along with the spacecraft in question.
*A Kugelblitz is a black hole formed entirely out of light, and is considered as a possibility for powering far future interstellar craft. You would need a lot of energy to create a Kugelblitz big enough to power a useful spaceship, as in capturing the entire output of the sun for some months or years, so creating them is one possible motivation for building a Dyson sphere (or swarm or whatever) in the first place.
Pretty sure that thermodynamics says you'll still see it. On the other hand if you're making a Kugelblitz you have to deal with the thermodynamics of that, I suppose. I'd have to think about that: I suspect the only way to do it is to make the sphere be completely reflective inside and then handle the light somehow.
But in the real world you'd see it.
Maybe I am wrong but if it collapsed, does that not spew out gravitational waves or a huge pulse of X-Ray?
If it has collapsed into a black hole then one would assume that light from more distant stars will now be bent. If it just disappeared then theoretically there should now be new things visible behind it. This of course is possibly beyond the observing power and instrument resolution we have.
A burst of energy occurs in some cases but not others, depending on mass and composition: https://en.wikipedia.org/wiki/Supernova#Core_collapse
It's a balancing act between mass and gravity pulling in, and radiation pressure pushing out. I would have thought If the star has enough mass, but did not get to fusing iron in the core, at some point, gravity takes over and the star could sort of do an oozlum bird and disappear up it's own singularity as gravity wins over, whatever the actual current composition of the star? I have no idea, I've watched too much star trek and not enough quantum physics.
Probably not been using an HP inkjet then; it would have jammed at least twice before the cartridges it came with ran out, and after the second set and five more jams some flimsy but essential part would have snapped, rendering the printer useless before even 9000 names had been printed.
Probably a Printronix belt printer that someone kept feeding boxes of greenbar, and fresh ink ribbons.
NASA have released "A Decade of Sun", images captures by the Solar Dynamics Observatory.
This 10-year time lapse showcases photos taken at a wavelength of 17.1 nanometers, which is an extreme ultraviolet wavelength that shows the Sun’s outermost atmospheric layer — the corona.
Maybe, and this is just a guess, when it went bang, and became a black hole, the hole then sucked in all the light, and no photons were quick/far enough away to get to our telescope ? Why we didn't see it go bang, You know what it's like when you first wake up, just want to stuff your face.
This could be either:
a) The collective failure of a relatively small amount of equipment and / or data analysis in looking at this star over a short period of time, or:
b) A once in a lifetime (of the human race) opportunity to observe and analyse whatever phenomenon caused it to 'disappear'.
You choose.
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