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The possible disappearance of a massive star in the galaxy PHL 293B

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Re: The possible disappearance of a massive star in the galaxy PHL 293B

#2
To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave.

Over maybe the last decade or so there's been some thought that if our simulations have trouble getting supernovae to explode, then perhaps nature has trouble getting supernovae to explode, too. Maybe a lot of massive stars just collapse directly into a black hole with no supernova. If this were the case then it would explain a discrepancy between the observed supernova rate and the total number of black holes; there seems to be about twice as many black holes as there are supernovae.

When I was in grad school one of the ongoing projects in my department was the so-called "Survey about Nothing" in which they took deep images of nearby galaxies and waited to see if any bright stars just... disappeared. (They did find one candidate: https://arxiv.org/abs/1411.1761)

The authors in this paper find another star that just disappeared. The trouble with all this is that if a star disappears it's unclear what exactly happened. Maybe it collapsed into a black hole, or maybe it just temporarily shrouded itself in dust and will be back in a few decades. The new thing about this star is that they have detailed spectra of the star prior to its disappearance, which helps tremendously with modeling the star. The hope is that with more detailed measurements they might be able to place limits on what is currently there and thereby figure out if a direct collapse happened or not.

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#3

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

IANAP and this could be a bit of a stretch, but could the disappearance of the star been caused by the completion of a Dyson sphere around it?

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#4

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

Thanks, very helpful.

I wonder if radio astronomy could put some limits on the obscured by dust scenario. I suppose it's unlikely for the star to be bright enough in such bands, would raise more questions than answers. But maybe astronomy is just one unlikely event after another.

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#5

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

If anything, the star certainly looks like a perfect candidate to go supernova…

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#6

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

IANAP and this could be a bit of a stretch, but could the disappearance of the star been caused by the completion of a Dyson sphere around it?

I'd imagine that such a completion would take long enough that we'd see it dimming (maybe irregularly) first. Then again I'd have thought so would a star collapsing...

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#7

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

Is there a project that shows which portions of the sky are currently viewed by which telescopes?

Also, how can researchers request/rent usage of telescopes (especially satellite-based ones)?

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#8
Sometimes astrologists make me smile:

> important sources of ionizing photons

Nothing better than a morning with cereal, milk and ionized photons.

Wikipedia says that LVB often form clouds around them from their violent outbursts that are sometimes miss-classified as supernovae. We will probably have to wait if it pops up again.

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#9

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

IANAP and this could be a bit of a stretch, but could the disappearance of the star been caused by the completion of a Dyson sphere around it?

It would be; first, spheres are unrealistic because of the stresses involved, so you'd be looking at a dyson swarm instead, and second, (and this is with sci-fi glasses on), even advanced civilizations would need many years to build one, so there would be a gradual fading instead.

Re: The possible disappearance of a massive star in the galaxy PHL 293B

#10

To provide a little bit of context for this work, one of the open questions in astronomy is how core collapse supernovae work. Computational scientists have struggled for a long time to get simulations of core collapse to explode. Typically to get an explosion they have to artificially insert a "piston" somewhere in the system that kicks the system outwards during the collapse and triggers the shock wave. Over maybe…

IANAP and this could be a bit of a stretch, but could the disappearance of the star been caused by the completion of a Dyson sphere around it?

If you are into these kinds of mysteries, I highly recommend reading Pandora's Star by Peter F Hamilton. (even more so if you want to spend a few days reading this epic space opera)
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