Mysteriously Variable Star Causes Speculation About Dyson Sphere (slate.com)

gurps_npc writes: Phil Plait just wrote an interesting article about a star that is extremely variable. We generally look for cyclical, minute (1%) variations in star light to detect planets. But we found one that has a variation in starlight of over 20%. We don't have a very good explanation for this, and some people are speculating that such variation could be caused by a civilization building a Dyson Sphere around the star. From the article: "Such a sphere would be dark in visible light, but emit a lot of infrared. People have looked for them, but we've never seen one (obviously). Which brings us back to KIC 8462852 (PDF). What if we caught an advanced alien civilization in the process of building such an artifact? Huge panels (or clusters of them) hundreds of thousands of kilometers across, and oddly-shaped, could produce the dips we see in that star's light." Plait says it's overwhelmingly unlikely, but interesting nonetheless.

Comments

Journalists doing all of the speculating

[Anonymous Coward]

It's important to note that the actual scientists studying the star aren't the ones screaming "ALIENS!" - that's the journalists who misreport and distort things to make them "sell better".

Re:Journalists doing all of the speculating

[quantaman]

It's important to note that the actual scientists studying the star aren't the ones screaming "ALIENS!" - that's the journalists who misreport and distort things to make them "sell better".

Actually these are the actual scientists studying the star, they aren't screaming aliens but they do seem to be saying something like "we can't figure out how to model this with any natural phenomena so lets see if non-natural hypothesis fit".

FTA:

When I spoke to Boyajian on the phone, she explained that her recent paper only reviews “natural” scenarios. “But,” she said, there were “other scenarios” she was considering.
Jason Wright, an astronomer from Penn State University, is set to publish an alternative interpretation of the light pattern. SETI researchers have long suggested that we might be able to detect distant extraterrestrial civilizations, by looking for enormous technological artifacts orbiting other stars. Wright and his co-authors say the unusual star’s light pattern is consistent with a “swarm of megastructures,” perhaps stellar-light collectors, technology designed to catch energy from the star.
[...]
Boyajian is now working with Wright and Andrew Siemion, the Director of the SETI Research Center at the University of California, Berkeley. The three of them are writing up a proposal. They want to point a massive radio dish at the unusual star, to see if it emits radio waves at frequencies associated with technological activity.

Re:Oh dear god.....

[dmgxmichael]

Jupiter seems to be at a curious point between being a planet and a star. Planets don't get much bigger, by volume, than Jupiter - they just start getting denser and denser until nuclear fusion begins. A brown dwarf an order of magnitude more massive than Jupiter would still be roughly the same size - so no, it's not a brown dwarf. Stars outright can be considerably smaller than the sun.

Re:Lots of other possibilities

[Electricity Likes Me]

Except if this were the case we would see diffraction spectra from the edge of the occluding object. We would also be able to find the object and measure it directly: in the attached paper they do a detailed follow up where no such occluding objects are discovered.

Re:Swarm, not sphere.

[Rei]

You know, right there in the abstract (don't even have to dig) is "... we conclude that the scenario most consistent with the data in hand is the passage of a family of exocomet fragments, all of which are associated with a single previous breakup event." They already have a hypothesis.

Re:Oh dear god.....

[blue9steel]

You are bad in math, are you? Or only bad in estimations?

The calculations have already been done, here is a quote from wikipedia "estimates that there is 1.82×1026 kg of easily usable building material in the Solar System, enough for a 1-AU shell with a mass of 600 kg/m2—about 8–20 cm thick on average, depending on the density of the material." Of course there are some debates as to whether that is sufficiently thick. Regardless of thickness there are a variety of design problems with the solid shell version and that's not what Dyson was actually proposing. A Dyson swarm or Niven ring would be much more practical.

Natural Explanations

[Kozar_The_Malignant]

FTFA, "we conclude that the scenario most consistent with the data in hand is the passage of a family of exocomet fragments, all of which are associated with a single previous breakup event." So yes, there are natural explanations.

Re:Coalescing gas clouds?

[Piata]

That's one of the most confusing parts though; the dips in light are not regular. From the article:

"It turns out there are lots of these dips in the star’s light. Hundreds. And they don’t seem to be periodic at all. They have odd shapes to them, too. A planet blocking a star’s light will have a generally symmetric dip; the light fades a little, remains steady at that level, then goes back up later. The dip at 800 days in the KIC 8462852 data doesn’t do that; it drops slowly, then rises more rapidly. Another one at 1,500 days has a series of blips up and down inside the main dips. There’s also an apparent change in brightness that seems to go up and down roughly every 20 days for weeks, then disappears completely. It’s likely just random transits, but still. It’s bizarre."

Re:Coalescing gas clouds?

[Rei]

You mean, like something broken up passing in front of the star? Which is the leading hypothesis presented in the paper?