Weird star changes in brightness due to... aliens?

[davidm]

Phil Plait has an interesting article concerning KIC 8462852 posted on Slate today.

It’s Still Probably Not Aliens, but That Weird Star Keeps on Getting Weirder

Then an announcement was made that over the past century or more the star has been fading at an unprecedented rate. This finding was immediately called into question, though, and the issue of fading remained unresolved.

But now a new study, using data from Kepler itself, shows that Tabby’s Star really is fading, and at quite a clip: Over three years of observation it faded by nearly 1 percent, then took a sudden nosedive, fading by two percent in the next 200 days.

…

Mind you, I’m still not saying aliens. I really and quite seriously don’t think that’s it. It’s more likely we’re seeing a combination of effects doing this; a cloud of material sliding in front of the star, dimming it slowly, with thicker clumps causing the sharper fading. But even that doesn’t explain all the data.

The only thing we know for sure is that we haven’t ever seen anything like this before, and that we are seeing is really, really weird.

[Sage_Rat]

I’m betting on an ocean of teapots.

I know they’re just floating out there!

[Lumpy]

One online commentator (sorry, lost link), noted that KIC 8462852 is a class F star, and wondered if the putative alien engineers were mining mass out of the star in order to extend its lifetime. I don’t suppose there are fewer class F stars in that vicinity than might be expected?

[davidm]

Could it be that they’re not even looking at what they think they’re looking at? Could it be that it’s not even a star but some sort of mirage caused by gravitational lensing or something?

I’m no astronomer, so someone will probably tell me why it’s a dumb idea.

[kaylasdad99]

@Projammer

Incomplete Dyson sphere or ring. Whether it hasn’t been finished or has been partially destroyed is the real question.

When one considers that the variations observed were caused by events that took place up to 1500 years ago, it would be surprising if the project had not already been completed. And perhaps subsequently destroyed.

“Idiot, you built it upside down! Tear it out and start over!”

[adaher]

Given that we learn brand new things about what is possible in the universe every time we send a probe to a planet or moon, I’d guess that what’s going on with this star is simply something we never imagined. Sure, it could be aliens. It could be something very mundane. Most likely though it’s simply a new natural phenomenon and unfortunately we don’t have the ability to go there anytime soon.

[Lumpy]

@kaylasdad99

When one considers that the variations observed were caused by events that took place up to 1500 years ago, it would be surprising if the project had not already been completed. And perhaps subsequently destroyed.

Although the star might be 1500 light-years away, unless faster-than-light travel is possible it’s pointless to discuss what might be occurring there “now”, since that’s effectively in our future. For purposes of discussion we can talk as if what we’re observing is happening currently.

[Doctor_Jackson]

This star serves as the stadium for the Intergalactic Calvinball League (ICL). The action in Calvinball, by it’s very nature (of which it has none) is cyclical. What one is observing is tens of millions of photographic flashes going off in unison as the spectators are awakened by the Potential Player Engagement Horn (which we should hear in another 900,000 years, give or take, so be sure to mark it on your calendar), then falling back to sleep as soon as they realize that nothing is actually happening. By the time we hear the horn, of course, the game will be nearing it’s conclusion. The next game will begin shortly thereafter, for varying values of shortly.

[Frodo]

@doctor jackson

this star serves as the stadium for the intergalactic calvinball league (icl). The action in calvinball, by it’s very nature (of which it has none) is cyclical. What one is observing is tens of millions of photographic flashes going off in unison as the spectators are awakened by the potential player engagement horn (which we should hear in another 900,000 years, give or take, so be sure to mark it on your calendar), then falling back to sleep as soon as they realize that nothing is actually happening. By the time we hear the horn, of course, the game will be nearing it’s conclusion. The next game will begin shortly thereafter, for varying values of shortly.

<Morbo> SOUND DOES NOT WORK LIKE THAT</Morbo>

[Duke_of_Rat]

A giant construction project large enough to block out 22% of the light from a star?

Yeah, that’s it.

[scr4]

@davidm

Could it be that they’re not even looking at what they think they’re looking at? Could it be that it’s not even a star but some sort of mirage caused by gravitational lensing or something?

I’m no astronomer, so someone will probably tell me why it’s a dumb idea.

Gravitational lensing by a foreground object could indeed alter the apparent brightness of a star. But it’s pretty much impossible for the foreground object to stay aligned with a star. Normally it’s just a blip as the object passes in front of the star.

[Frodo]

Vogon intergalactic highway construction project?

[Doctor_Jackson]

@Frodo

<Morbo> SOUND DOES NOT WORK LIKE THAT</Morbo>

I see that Mordo has not played much Calvinball. Physics is mostly optional and in some cases illegal.

[Chimera]

Well, people have commented in various places about how if this was a truly advanced society capable of making a Dyson Sphere, they’d be here by now.

1> We don’t know that they haven’t. Unless we’re super tasty or make excellent slaves, they’d have zero reason to come here. Hell, they wouldn’t even necessarily need to keep tabs on us, because…
2> There are quite literally tens or even hundreds of millions of stars in a sphere of 1540 light year radius. They would have zero need for our resources all the way out here.
3> By the time we developed FTL and one of our exploration ships stumbled upon one of their ships or outposts, they’d still be so far ahead of us and so well developed that they could either tell us where our borders are, or tell us we’re now part of their empire, and there’d be fuck-all we could do about it.

[davidm]

FTL is very likely impossible, so it’s not likely they’d be able to come this far no matter how advanced they are.

I suppose that they could send a probe or probes but there are problems with that.
[ul]
[li]It would have to remain functional for thousands of years.[/li][li]They’d have to be willing to put resources into something that wouldn’t be heard from for thousands of years.[/li][/ul]

[davidm]

There’s some new data for this star. We know that there’s been a constant dimming for a least 100 years, but it appears that there’s been more rapid dimming more recently.

http://www.skyandtelescope.com/astronomy-news/tabbys-star-weird-star-gets-weirder/

Now, a new study has appeared on the scene: Benjamin Montet (Caltech and Harvard-Smithsonian Center for Astrophysics) and Joshua Simon (Observatories of the Carnegie Institution of Washington) have investigated Kepler data to look for longterm trends. If there had been a century-long dimming of 0.16 magnitude, Kepler ought to have seen a loss of several thousandths of a magnitude during its first, 4-year mission — it was exactly the kind of precision experiment the satellite was born for.
…
For the first 3 years, the star faded at a rate of 0.3% per year, equivalent to 0.37 magnitudes per century and more than double what Schaefer had found in the DASCH data. Then, for almost seven months, the star suddenly began dimming even more rapidly, at a rate of 2.5% per year. The sudden decline came to a halt before Kepler’s initial mission ended, but it’s not clear if the light curve flattened out or returned to its previous dimming pattern in those remaining months.

The results appear to support Schaefer’s assertion that the star is in longterm decline, though they can’t directly confirm the century-long trend since Kepler’s observations are limited to four years.

The results also put the “comet swarm” scenario to rest. “It was already pretty contrived to invoke a swarm of comets to explain the data,” Boyajian says. “The Montet and Simon results put an additional tremendous strain on it!”

So if this is correct then “comets” is not the likely answer.

Then there’s this…

Researchers Just Found a Second 'Dyson Sphere' Star

The researchers report that over 78.8 days of observations, EPIC 204278916 displayed irregular dimming of up to 65 percent for around 25 consecutive days.
…
The German team behind the new EPIC 204278916 observations suggests that its massive dips in the light curve could be caused by the existence of a protoplanetary disk that’s oriented ‘edge-on’ in relation to Earth. That orientation could mean it’s not only blocking the light from the star at certain times, we’re also at the wrong angle to be viewing its own infrared radiation.

That article has a possible explanation for EPIC 204278916 that it says may also be applicable to KIC 8462852. Although I’m not sure how it would explain the long term dimming.

[davidm]

They’ve apparently found another star with similar behavior.

Have Astronomers Found Another "Alien Megastructure" Star?

Known as VVV-WIT-07, the star appears to be much older and redder than our sun, although the amount of interstellar dust between our solar system and the star’s home closer to the galactic center makes exact classification and distance measurements very difficult. What is certain is that in the summer of 2012, the object’s brightness faded slightly for 11 days, then plummeted over the following 48 days, suggesting that something blocked more than three quarters of the star’s light streaming toward Earth. But what could that “something” be?

[EastUmpqua]

@davidm

FTL is very likely impossible, so it’s not likely they’d be able to come this far no matter how advanced they are.

I suppose that they could send a probe or probes but there are problems with that.
[ul]
[li]It would have to remain functional for thousands of years.[/li][li]They’d have to be willing to put resources into something that wouldn’t be heard from for thousands of years.[/li][/ul]

Yep. That’s exactly (ok my opinion) what Oumuamua just did. It slapped us on the ass, executed an efficient gravity assist around our own star, got what it wanted, and took off. I don’t think FTL travel or communication is possible. I hope I’m right.

[Darren_Garrison]

Oumuamua is traveling very, very, very slow for an interstellar spacecraft. On the order of 1/100th of one percent of the speed of light. Around half the speed of Voyager 2. If aliens sent it, they must have been the Pakled.

[Slash1972]

Maybe when it gets out of range of anything we have that can detect it, it speeds up?