[Bobboau]

http://www.slate.com/blogs/bad_astronomy/2015/10/14/weird_star_strange_dips_in_brightness_are_a_bit_baffling.html

[Turambar]

It might not be aliens.  We might be in an all-human universe.

Someone should model a ringworld and spin it around a star at a few angles relative to earth and see what kinds of patterns come up.

[watsisname]

The scientific procedure for forming conclusions on bizarre astronomical data:
Try to think of all possible scenarios that might explain what is happening, and model them.  Check if the models produce predictions that are consistent (nor not!) with the observations.  Make more observations to test those models further.  See if you can isolate a single working hypothesis.

The whack-job procedure for forming conclusions on bizarre astronomical data:
"I can't explain it, therefore it's aliens!"

How good popular science reporting makes a headline:
"Have We Detected Megastructures Built By Aliens Around A Distant Star?
Popular Science‎ - 1 day ago"

How whack-job popular science reporting makes a headline:
Alien 'MEGASTRUCTURE' found as bizarre star is blocked by huge object | Daily Mail Online
Daily Mail‎ - 1 day ago

Whatever is going on around that star, it's pretty damn interesting, whether involving natural astrophysics or otherwise.  Myself and I think most of my mates are of the view that "comets and a lot of cool, optically thick dust" is the most likely among the working hypotheses.  But damn would it be mindblowing if it's really a Dyson sphere (or ringworld).

[Luis Dias]

Whatever it is it seems really weird stuff is happening there I'd love for there to be a push for more research into this star. Weird natural phenomena is always fascinating.

[jr2]

Plot twist: the artificial world is uninhabited, with no clue left as to where the former occupants went.

[watsisname]

My favorite theory: 

It's just a bunch of comets and dust, stirred up in weird and surprising ways by aliens in order to distract our attention as they set up camp in our outer solar system.

And yes, they knew exactly where and with what technology we'd be searching 1500 years in advance, because ****, guys, they're aliens, I ain't got to explain ****.

My other favorite theory:   It's the scramblers. 

[zookeeper]

It'd be an interesting situation if we'd actually find some massive alien construction like that, or could otherwise observe their civilization. We'd still not be able to do anything about it, we'd just be stuck here looking at what they're doing for thousands of years without any means of communication. How would that long-term awareness of a distant alien civilization affect things here?

[Luis Dias]

It would be such a massive boon for space exploration budgets it's not even funny.

You'd see tech billionaires scrambling to get their uber mega brilliant space telescopes trying to preen on these aliens' structures so they could get some glimpse of new technologies they could eventually understand and develop. It'd definitely spark the second space age.

[The E]

Yeah, stuff like this is like the Everest: Once we see a mountain, there's a percentage of the population who will do everything in order top be able to climb that thing and plant a flag on it.

[X3N0-Life-Form]

My other favorite theory:   It's the scramblers. 

If that's the case, then this is just a diversion while sneak up on us from somewhere else.

[Bobboau]

the most powerful listening devices conceivable would be built, purpose built just to listen to this one point in the sky. maybe we can pick up some stray transmissions, maybe those transmissions mention something about how they do things, maybe we can reverse engineer it.

[qwadtep]

Plot twist: the artificial world is uninhabited, with no clue left as to where the former occupants went.

There was a Star Trek TNG episode with exactly this plot. Ships kept crashing into a Dyson Sphere because nobody realized there was a star there until they were trapped by the gravity, and when the Enterprise investigates it turns out the thing's already abandoned because the star is old and unstable.

It would be such a massive boon for space exploration budgets it's not even funny.

You'd see tech billionaires scrambling to get their uber mega brilliant space telescopes trying to preen on these aliens' structures so they could get some glimpse of new technologies they could eventually understand and develop. It'd definitely spark the second space age.

Not just for space exploration. Metallurgy, chemistry, engineering; basically every hard science would be kicked into high gear in response to the sudden proof that technology so far beyond our own is even possible, and you can bet your Sathanas rear beam cannon that funding research into it would be a priority, because not only is it possible but something out there has already done it and our species is hopelessly outmatched if they turn out to be unfriendly.