Merged Tabby's Star / One Scary Star

[Fudbucker]

There's a Scientific American article about that star that periodically dims. One of the claims struck me as strange:

"So what is blocking out the light from Tabby's Star? Well, an astronomer's kneejerk reaction is to try to concoct some model that might explain the observations. We've all been tossing out ideas. The trouble is that our ideas founder on the lack of infrared excess. We can imagine accretion disks with flaring edges, or complex multiple star systems with improbable orbits, or vast streams of super-giant comets, or dusty asteroid-asteroid collisions. But all of these require an infrared excess. This includes the suggestion that the dips in brightness might be caused by some partially-constructed artificial “Dyson Sphere” built by a very advanced civilization around the star."
http://blogs.scientificamerican.com/guest-blog/the-most-mysterious-star-in-the-galaxy/

Wouldn't it be possible (in theory) to construct a mega-structure that converts excess heat energy to some other form of energy that we couldn't detect from this range?

 

[WhatRoughBeast]

There's a Scientific American article about that star that periodically dims. One of the claims struck me as strange:

Wouldn't it be possible (in theory) to construct a mega-structure that converts excess heat energy to some other form of energy that we couldn't detect from this range?

Yes, but it would be an artificial structure on a par with a Dyson's sphere. It would also imply that the other form of energy is being beamed away from the system. If the energy is consumed in the system, it must show up as heat - that's the final waste product of any energy process.

Astronomers are not yet ready to declare that such structures (and the civilizations implied) exist.

Give 'em time.

 

[Fudbucker]

Yes, but it would be an artificial structure on a par with a Dyson's sphere. It would also imply that the other form of energy is being beamed away from the system. If the energy is consumed in the system, it must show up as heat - that's the final waste product of any energy process.

Astronomers are not yet ready to declare that such structures (and the civilizations implied) exist.

Give 'em time.

But it would be possible to convert the excess heat energy to something like microwaves, right? I mean, if one posits mega-structures (not necessarily a full-on Dyson sphere) as being responsible for the dimming, an objection about excess heat not being detected could be overcome by conjecture that the heat is being converted to other forms of energy.

If the author of the article was willing to mention mega-structures, why wasn't a caveat about converting heat energy included in the article? Should it have been included, or is such speculation totally absurd?

 

[WhatRoughBeast]

But it would be possible to convert the excess heat energy to something like microwaves, right?

OK, the star's energy has been converted to microwaves. Now what? Eat them? If you use the microwaves as a power source, as envisioned in most Solar Power Satellites) the receiving end will then convert them to something useful, like, for instance, heat or light. Any mechanical motion eventually gets converted to heat, too.

The exception is if, as I mentioned, you beam the microwaves out of the system for use somewhere else.

 

[rjh01]

OK, the star's energy has been converted to microwaves. Now what? Eat them? If you use the microwaves as a power source, as envisioned in most Solar Power Satellites) the receiving end will then convert them to something useful, like, for instance, heat or light. Any mechanical motion eventually gets converted to heat, too.

The exception is if, as I mentioned, you beam the microwaves out of the system for use somewhere else.

I like that idea. Have heaps of solar cells orbiting the star at various distances. These convert the radiation into another form of energy. They might split water into hydrogen and oxygen which is then collected. Or, as you say, converted into microwaves and beamed out of the system.

Each time one of these solar cells passes between us and the star we see the dip. This means they are massive things.

I have called them solar cells, but they might be something else that does the same function.

 

[Fudbucker]

I like that idea. Have heaps of solar cells orbiting the star at various distances. These convert the radiation into another form of energy. They might split water into hydrogen and oxygen which is then collected. Or, as you say, converted into microwaves and beamed out of the system.

Each time one of these solar cells passes between us and the star we see the dip. This means they are massive things.

I have called them solar cells, but they might be something else that does the same function.

Or maybe they're converting energy to matter (or creating anti-matter).

 

[crescent]

Giant mirrors, reflecting the star's light towards... something. Another star, another civilization. They can be adjusted to aim towards multiple points, perhaps. The receiving point sees flashes of light coming from the star, the pattern of the flashes carries data.

Unfortunately, none of the data is reflected towards us.

 

[WhatRoughBeast]

Giant mirrors, reflecting the star's light towards... something. Another star, another civilization. They can be adjusted to aim towards multiple points, perhaps. The receiving point sees flashes of light coming from the star, the pattern of the flashes carries data.

Great. Spam on a galactic scale.

 

[Puppycow]

What about this hypothesis:

The star was occulted not by debris in its own system but by something much smaller in our own solar system. A loose agglomeration of broken up comet pieces, say.

Would that explain the observations and resolve the mystery?

 

[Mark6]

What about this hypothesis:

The star was occulted not by debris in its own system but by something much smaller in our own solar system. A loose agglomeration of broken up comet pieces, say.

Would that explain the observations and resolve the mystery?

No. Any such debris in our solar system would remain in front of Tabby's star for a few minutes at most, as Earth moved in and out of alignment. Dimmings of Tabby's star lasted between 5 and 90 days.

 

[Puppycow]

No. Any such debris in our solar system would remain in front of Tabby's star for a few minutes at most, as Earth moved in and out of alignment. Dimmings of Tabby's star lasted between 5 and 90 days.

How long has the star been observed I wonder?

Maybe something halfway between us and the star? A smashed-up rogue planet which has been ejected into deep space for example?

ETA: or maybe a cloud of dust in interstellar space.

 

[rjh01]

What about this hypothesis:

The star was occulted not by debris in its own system but by something much smaller in our own solar system. A loose agglomeration of broken up comet pieces, say.

Would that explain the observations and resolve the mystery?

No. Any such debris in our solar system would remain in front of Tabby's star for a few minutes at most, as Earth moved in and out of alignment. Dimmings of Tabby's star lasted between 5 and 90 days.

If it was something other than in Tabby's system then it would also impact on other stars. This does not happen.

 

[Mark6]

How long has the star been observed I wonder?

Maybe something halfway between us and the star? A smashed-up rogue planet which has been ejected into deep space for example?

ETA: or maybe a cloud of dust in interstellar space.

What rjh01 said. Any cloud of debris in interstellar space large enough to block Tabby's star for 5-90 days, would block the visually nearby stars as well.

 

[Puppycow]

OK, so we are left with some sort of stellar phenomenon that current theories can't account for as the most plausible explanation?

That we don't yet have a complete scientific model for everything seems like the most likely possibility to me. I really doubt that super-advanced intelligent aliens is the reason.

 

[Puppycow]

If it was something other than in Tabby's system then it would also impact on other stars. This does not happen.

What rjh01 said. Any cloud of debris in interstellar space large enough to block Tabby's star for 5-90 days, would block the visually nearby stars as well.

One final try at this: A cloud of dust or debris that is much closer to Tabby's star than to us? Just outside of its influence. So it would not block the nearby stars but is far enough away so that it doesn't get significantly heated up?

 

[rjh01]

One final try at this: A cloud of dust or debris that is much closer to Tabby's star than to us? Just outside of its influence. So it would not block the nearby stars but is far enough away so that it doesn't get significantly heated up?

Maybe as far away as the sun is from pluto maybe? The problem is that it would be very big. One thing that could be is a massive number of small particles. I think it would need to be too massive to exist.

 

[Roboramma]

Perhaps it's an interstellar object (nebular or whatever) that's drifted near to Tabby's star but hasn't had time to be heated up.

Or it's a part of the system that's on a very eliptical orbit and we're seeing the part that's close to the star (which doesn't stay long enough to get heated up). There's some time lag before it starts emitting infrared, and when it does it's at a different part of it's orbit.

 

[Puppycow]

Maybe as far away as the sun is from pluto maybe? The problem is that it would be very big. One thing that could be is a massive number of small particles. I think it would need to be too massive to exist.

Farther than Pluto. You know about Sedna or the hypothetical ninth Neptune-sized planet they think might be out there? These objects make Pluto's orbit look close by comparison.

But not a planet, a cloud of dust or the like. Far enough away so that it doesn't get hot and emit IR light, but occults the sun.

 

[rjh01]

Perhaps it's an interstellar object (nebular or whatever) that's drifted near to Tabby's star but hasn't had time to be heated up.

Or it's a part of the system that's on a very eliptical orbit and we're seeing the part that's close to the star (which doesn't stay long enough to get heated up). There's some time lag before it starts emitting infrared, and when it does it's at a different part of it's orbit.

Farther than Pluto. You know about Sedna or the hypothetical ninth Neptune-sized planet they think might be out there? These objects make Pluto's orbit look close by comparison.

But not a planet, a cloud of dust or the like. Far enough away so that it doesn't get hot and emit IR light, but occults the sun.

If it was a once off dip your opinion might be valid. But it falls apart when there are several dips. The diagram in the link in the OP shows 3 dips over a month apart.

 

[JeanTate]

Here's an interesting question: how would you test any of the ideas put forward to explain the optical (Kepler) data?

Specifically, what telescopes (etc) would you point towards the star (or nearby)? What sorts of signatures would you look for? Would observing in something other than the electromagnetic spectrum - neutrinos, say, or cosmic rays - help to test at least some of the ideas?