Massive Star " Vanishes "

Third choice, the little christmas tree bulb burnt out.

originally posted by: Ophiuchus 13
Maybe being 70 million light years away we are just observing the end processes that may have started 70 million years ago.
a reply to: alldaylong

Whatever they see now, happened 70 million years in the past. Amazing isn't it..makes my head hurt to think of the scale of it all.

originally posted by: buddha
You soon forget!
this is the second one.
they said that one was a Dyson sphere.

the stars arecgoing out!

Nah,
David Copperfield is practicing.

It is a odd perception to consider and process indeed.

a reply to: vonclod

Probably just a massive space dust cloud passing between the earth and the light coming from the star.

it self isolated is my guess a reply to: HalWesten

a reply to: CraftyArrow

surely they would have noticed a gradual dimming of the star as the construction of the dyson sphere neared completion
the dimming would regular based on the work schedule

unless the aliens are able to instantly manifest objects into matter with nothing but will power

a reply to: odzeandennz

I always say that society will look back at us and our "Drug War" as barbaric. Just as we look back on society and their use of lobotomies.
Locking non violently people that need help up, without addressing any underlying issues causing said addiction. Barbaric.

To be on topic, I was hoping for a dyson sphere : )

a reply to: neutronflux

That would likely be a gradual dimming, akin to what we saw with Betelgeuse.

a reply to: alldaylong

When a star collapses into a black hole, doesn't it create gravity waves which can be detected? Wondering if they were able to see this.

originally posted by: theatreboy
It never ceases to amaze how we think we know it all know. It would be highly unusual for this to happen?!!

How long has the universe been around versus us? Maybe supernova are the exception and not the rule. I mean, we never had telescopes until when?

We need to get over ourselves.

Nobody is saying we think we know it all, we learn new things all the time in astronomy.

If you want to know what the scientists who made the discovery say, you have to read their paper, not what some media article says about it. So what do the scientists say in their paper?

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

There is considerable debate on the end stages and fate of the most massive stars.

Does that sound like "we think we know it all"? It seems to me like the implication of that is, the reason it's being debated is because we don't really know for sure.

So you might want to follow Mark Twain's advice to "“Get your facts first, and then you can distort them as much as you please.”

originally posted by: openminded2011
a reply to: alldaylong

When a star collapses into a black hole, doesn't it create gravity waves which can be detected? Wondering if they were able to see this.

The inverse-square law determines energy versus distance for an isotropic source, so at 10 times the distance we only observe 1/100 the energy.

Gravity waves are not what you mean, they are something else, you mean gravitational waves, which the first detection by LIGO was from a back hole merger something like 1.3 billion light years away. The energy released by that event was beyond comprehension on human scales, and it was also many times more powerful than the most powerful supernova ever observed.

As far as I know, gravitational waves from a supernova (a form of star collapse into a black hole) have never been detected, but what have been detected from a "nearby" supernova in 1987 were neutrinos, since supernovas resulting from star collapse give off many neutrinos. There is a paper saying we might be able to detect gravitational waves from a nearby core-collapse supernova. I couldn't find where they defined "nearby" except they used an example of 33,000 light years away or so for gravitational wave detection, which if that's what's meant by "nearby", the supernova would have to be not only in our galaxy, but in our "corner" of our galaxy.

The star you're asking about was something like 70,000,000 light years away, far outside our galaxy, so if we would need to be within something like 33,000 light years to detect those gravitational waves, you can hopefully see why that current technology won't help with something so far away.

The neutrino detection from the 1987 supernova was only a total of 25 neutrinos, from a distance of 168,000 light-years. For a similar event at 70 million light years away, due to the inverse-square law, we might not detect any neutrinos and even if we detected one or two they would not be above "background" most likely.

So while neutrino and gravitational wave detection might occur from "nearby" core-collapse events, 70 million light years away is not "nearby" so I doubt they will be of much help at that distance, with current technology.

originally posted by: bigfatfurrytexan
a reply to: neutronflux

That would likely be a gradual dimming, akin to what we saw with Betelgeuse.

Why? Because it doesn’t fit a narrative you want?

originally posted by: neutronflux

originally posted by: bigfatfurrytexan
a reply to: neutronflux

That would likely be a gradual dimming, akin to what we saw with Betelgeuse.

Why? Because it doesn’t fit a narrative you want?

Narrative?..want?

Interesting response

a reply to: openminded2011

I think the issue is, the star itself wasn't really visible to begin with. Its presence was intuited via mathematics and its subtle effects. And its vanishing didn't get witnessed. One time some measurements were taken and it was there...another time measurements were taken and it wasn't.

It could be all sorts of things. The dust cloud, although its effect would be gradual and would require a good amount of times between measurements to not detect. The unicorn of black hole formation (it just fizzles out and collapses vs going supernova) is another theory.

But it could be literally all sorts of things. Maybe even an effect of gravity (lensing). I dunno.

originally posted by: neutronflux

originally posted by: bigfatfurrytexan
a reply to: neutronflux

That would likely be a gradual dimming, akin to what we saw with Betelgeuse.

Why? Because it doesn’t fit a narrative you want?

What the hell kind of response is that? LOL

FWIW, i don't want a narrative. I want to explore the mysteries before us. I have no preconceptions that I hold dear.

originally posted by: neutronflux
Probably just a massive space dust cloud passing between the earth and the light coming from the star.

The cloud wouldn't even have to be that large, if it was near the edge of that galaxy when it blocked out the light from the star.

In 200,000 years, the star will be visible again. The cloud will have moved far enough to no longer obstruct our view.

To be factual, we have no proof the star actually, physically, vanished. Rather, we stopped detecting the signs/signals that the star was there. That star is in another whole galaxy, it's not like we even had a picture of it.

So, several things could have happened: turning into a balck hole without going supernova, dimming due to some stellar processes, or just getting obscured by a massive cloud of dust.

I think the star is still there, but has had something happen like a huge sunspot or multiple sunspots event causing major dimming.

Our own sun has had huge sunspots before, one grouping AR12192 was the size of Jupiter in October 2014.

Just about any violent end of a star ,novae, super novae, should be accompanied by a noticeable /increase/ in luminosity.

The first thought I had was a Dyson sphere, although as someone else pointed out earlier, one would expect that would be a gradual dimming if the construction were carried out over some time interval. Then again, that's our bias thinking as human beings. We haven't the faintest clue how such a device would be constructed and put in place, perhaps it was built away from the the star (less radiation and gravity) and moved into position after completion. Perhaps the builders have 'window shade' effect where they can quickly reverse the sphere's energy capture as a safety mechanism. Nobody knows the details.

I also liked the thought of some non-luminous body, like a gas cloud or debris field, becoming interposed between the star and ours, but I'm not sure a cloud of gas or asteroid field could truly block out all the star's light.

Consider also the effect of gravitational lensing. The star that is apparent to us in that position of the sky /might not physically be there/, but rather an optical illusion created by some enormous source of gravity (e.g. black hole) that bends the star's light. If something were to happen to the source of gravity causing the lensing, odd visual phenomenon would occur, including stars moving about the sky suddenly.

It also may not have been a star at all, but some artificial light source (not naturally occurring) that is no longer luminous, although that seems a bit far fetched.

Nothing seems to be definitive at this point.