Astronomers may have found giant alien 'megastructures' orbiting a star in the Milky Way

[Nothalogh]

2 minutes ago, Spaceception said:

Party in the Kepler house! Whoop, whoop!!

Think of it, an artificial pulsar

[Spaceception]

2 minutes ago, Nothalogh said:

Think of it, an artificial pulsar

That's one crazy awesome disco party.

[fredinno]

50 minutes ago, Spaceception said:

That's one crazy awesome disco party.

Not to mention one that everyone would die in due to intense ionizing radiation...

[Spaceception]

Just now, fredinno said:

Not to mention one that everyone would die in due to intense ionizing radiation...

That too.

 

 

Radiation! Radiation! Radiation!

[fredinno]

On 11/4/2015 at 3:16 PM, DBowman said:

The two earth year periodicity is nagging at me...

 

1. It's just coincidence: okay sure, but weak. What are the odds that the only thing we've seen like this happens to have a 'resonance' with Earths orbit around the sun?
2. It's earth's motion around the sun bringing the object into occultation: what does this say about where it is and how big it is? I can only think of 'it's not orbiting the star, it's between us and the star' - any other possibilities?
3. ??? what are the other options?

 

Probably a coincidence- the galaxy is enormous, so it might just have an appox. 1:2 resonance, just out of luck.

[kerbiloid]

Once the Dyson Sphere will be finished soon, next five hundred years the aliens will be thinking:

- We did it!!! But what for?..

[Aethon]

ABSTRACT

The F-type star KIC 8462852 has recently been identified as an exceptional target for SETI (search for extraterrestrial intelligence) observations. We describe an analysis methodology for optical SETI, which we have used to analyse nine hours of serendipitous archival observations of KIC 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon m−2 , is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.

 

A search through archived data for optical pulses from Tabbys' star published February 3, 2016.

http://arxiv.org/pdf/1602.00987v2.pdf

[Findthepin1]

1 minute ago, Aethon said:

ABSTRACT

The F-type star KIC 8462852 has recently been identified as an exceptional target for SETI (search for extraterrestrial intelligence) observations. We describe an analysis methodology for optical SETI, which we have used to analyse nine hours of serendipitous archival observations of KIC 8462852 made with the VERITAS gamma-ray observatory between 2009 and 2015. No evidence of pulsed optical beacons, above a pulse intensity at the Earth of approximately 1 photon m−2 , is found. We also discuss the potential use of imaging atmospheric Cherenkov telescope arrays in searching for extremely short duration optical transients in general.

 

A search through archived data for optical pulses from Tabbys' star published February 3, 2016.

http://arxiv.org/pdf/1602.00987v2.pdf

What does this mean?

[Rakaydos]

1 hour ago, Findthepin1 said:

What does this mean?

the're checking if aliens are shning giant lasers at us to try and communicate. They didnt find any in the information they looked through. (9 hours f observation over 6 years)

[Streetwind]

Admittedly, if there were hyper-advanced aliens on that star, with the ability to build giant lasers to attempt communication, they probably wouldn't shine any at us. At a distance of 1480 light years away, it would take until our year 3450 or so for them to realize that we as a civilization have developed the technology necessary to receive such signals; and then, until our year ~4930 or so for any giant laser beams shining in our direction to arrive back at Earth... even if they literally went right for it.

And I'm saying this not as a "I believe there's aliens" thing, but rather as a "interstellar distances just blow my mind" kind of thing.   I mean, it's barely even been 250 years since the dawn of the steam engine and 75 years since the invention of the electric computer, and look where we are today. Just try to imagine how two advanced civilizations, trying to communicate with each other across a 1500 lightyear gap, would develop during the communications delay.

[Findthepin1]

9 hours ago, Rakaydos said:

the're checking if aliens are shning giant lasers at us to try and communicate. They didnt find any in the information they looked through. (9 hours f observation over 6 years)

The aliens wouldn't know we exist. How would they? As far as they know, we're not even a bunch of medieval people yet. As far as they can see, we're not landing on the Moon and sending radio signals into space. We're too busy domesticating silkworms, colonizing Scotland, battling King Arthur, inventing matches, changing the Eastern Roman Empire's official language, and sailing to Antarctica in canoes. And they can't see, because they have no reason to look in our direction. None of our signals have reached that star. It will be at least another 1300 years before they even know we exist.  

Edited March 24, 2016 by Findthepin1

[Streetwind]

52 minutes ago, Findthepin1 said:

The aliens wouldn't know we exist. How would they? As far as they know, we're not even a bunch of medieval people yet. As far as they can see, we're not landing on the Moon and sending radio signals into space. We're too busy domesticating silkworms, colonizing Scotland, battling King Arthur, inventing matches, changing the Eastern Roman Empire's official language, and sailing to Antarctica in canoes. And they can't see, because they have no reason to look in our direction. None of our signals have reached that star. It will be at least another 1300 years before they even know we exist.  

Not necessarily. Planetary atmospheres can theoretically be analyzed by telescopes over vast distances, limited only by the resolution of the telescope. We're doing stuff like that today, already, in a limited fashion. A civilization sufficiently advanced to build "giant megastructures" around their host star might be able to do this from 1500 lightyears away. And Earth's atmosphere is exceedingly unusual; we haven't seen anything like it on any exoplanet yet. The presence of large amounts of biologic activity radically changes it from what you would normally expect for a dead planet. Any sufficiently advanced outside observer should be able to look at Earth from afar and say "yep, that right there is probably a world bearing carbon-based life" with a fairly high confidence.

It's just that they have absolutely no reason to try and communicate with a world that shows signs of life, but zero signs of intelligent life. We just haven't existed for long enough as a technology-based civilization to advertise this fact to the galaxy at large. Life by itself can exist for billions of years without becoming self-aware. It's pointless to try.

Unless the strange light dips of that star are a communication attempt in itself. Which is possible, since (as we see with out current situation) few things are more likely to rouse extreme suspicion in astronomers of another species as a random star exhibiting an unexplainable phenomenon like strong, periodic dimming. You could achieve this by putting an absurdly large sunshield into solar orbit, which repeatedly causes the dimming effect from the eyes of a distant observer everytime it passes by. It's like a giant cosmic billboard screaming "look at me! look at me!". Though unfrtunately this theory fails to explain all of the behavior data that's been gathered so far, so it's unlikely to be a cosmic billboard.

 

Edited March 24, 2016 by Streetwind

[Aethon]

The most exciting fact to me is this : 

"Archival photographic plates also show unprecedented century-long dimming, at an average rate of 0.165 ± 0.013 magnitudes per century." 

Any advanced society worth it's salt would certainly know the Earths' atmospheric composition is unnatural.

Hopefully future study will determine if the objects causing the dimming of Tabbys' star are unusually shaped.  A giant triangle would certainly be a cheap way to notify other intelligences that intelligent life dwells there. 

[SuperFastJellyfish]

According to a commenter(Eniac) on this article from 2009:
 

Quote

 

Here are some back-of-the-envelope calculations on the solar gravitational telescope:

Assume we are at f = 670 AU ~ 1E14 m.
Assume the Einstein radius there is twice solar radius r ~ 1.5E9 m
Distance to object is d = 10 ly ~ 1E17 m
Wavelength of light lambda = 500 nm = 5E-7 m

1) The distance vs. focal length ratio is d/f = 1E3, one thousand. That means that a 1 meter pixel-to-pixel detector will have a resolution of 1 km at the target system, which is quite phenomenal. There are at least two things that can keep that from happening: a) the diffraction limit, and b) resolving the Einstein ring from the sun requires a pixel aperture much larger than a meter.

2) Diffraction limit: The resolution limit due to diffraction is 1.22*d*lambda/r ~ 4 m. Well below our pixel resolution, so we are good with that.

3) pixel size: we need to resolve the Einstein ring from the sun. Angular resolution for the pixel telescope needs to be r/f ~ 1.5E-5, requiring a minimum aperture of a = 1.22*lambda*f/r ~ 4 cm. We are good with that also.

So far, unless I have miscalculated, it looks like 1 km resolution is feasible and could even be improve by a factor of twenty or so to reach ~50 meters, based on diffraction and pixel size. There are, however, at least two more potential problems: light gathering power and tracking.  These are somewhat more difficult to deal with, perhaps I’ll take a stab some other time. Anyone know if, how, and where these things have been worked out before?

Note that small lambda here has a very beneficial effect and things would look much less rosy in the radio range.

 

Bold is mine.

If we take his calculations to be true, then a civilization that noticed Earth's interesting atmospheric composition may have positioned a gravitational lensing telescope to view us in amazing detail already.

[Findthepin1]

3 hours ago, SuperFastJellyfish said:

According to a commenter(Eniac) on this article from 2009:
 

Bold is mine.

If we take his calculations to be true, then a civilization that noticed Earth's interesting atmospheric composition may have positioned a gravitational lensing telescope to view us in amazing detail already.

Would they have seen our stuff?

Edited March 24, 2016 by Findthepin1

[justidutch]

7 hours ago, Streetwind said:

...Unless the strange light dips of that star are a communication attempt in itself. Which is possible, since (as we see with out current situation) few things are more likely to rouse extreme suspicion in astronomers of another species as a random star exhibiting an unexplainable phenomenon like strong, periodic dimming. You could achieve this by putting an absurdly large sunshield into solar orbit, which repeatedly causes the dimming effect from the eyes of a distant observer everytime it passes by. It's like a giant cosmic billboard screaming "look at me! look at me!". Though unfrtunately this theory fails to explain all of the behavior data that's been gathered so far, so it's unlikely to be a cosmic billboard.

 

they're communicating via morse code!!!

[YNM]

Have anyone taken the spectra of the star ? Funny to see that it's not surrounded by debris field yet people still theorize about debris plane... you should've saw it when taking things in infrared vs taking things in visual !

EDIT : For those interested in gravitational lensing, I made this post far back then. Yeah, LGP won't be great.

Edited March 25, 2016 by YNM

[kerbiloid]

14 hours ago, Streetwind said:

It's like a giant cosmic billboard screaming "look at me! look at me!"

- One, two, three... One, two, three... Test, test... Okay, it works, now switch off.

[magnemoe]

On 24.3.2016 at 5:41 PM, Aethon said:

The most exciting fact to me is this : 

"Archival photographic plates also show unprecedented century-long dimming, at an average rate of 0.165 ± 0.013 magnitudes per century." 

Any advanced society worth it's salt would certainly know the Earths' atmospheric composition is unnatural.

Hopefully future study will determine if the objects causing the dimming of Tabbys' star are unusually shaped.  A giant triangle would certainly be a cheap way to notify other intelligences that intelligent life dwells there. 

This is interesting as in the effect has to be more than an century old. 
One issue with this being an artificial structure is that it sounds to me being to far from the sun, is it outside the Goldilocks zone?
You would either put something like this as close as possible without burning up the solar panels if you do power generation for beamed power. 
If you use it to power industrial infrastructure putting it in the same orbit as the main planet makes sense for easier travel, you would probably move out once the orbit around the planet is too crowded, keeping in planetary orbit will make travel easier. Putting it farter out would increase size requirements for solar panels with no benefits.

And yes aliens doing stuff like this should know that earth has life, they know its plenty of life on land.
If gravitational lensing work as well as described above they might be able to see fields and cities both would point toward intelligent life. 
Distance is however far to long for any mission. 

Edited March 26, 2016 by magnemoe

[Exploro]

On 3/24/2016 at 11:00 AM, Findthepin1 said:

The aliens wouldn't know we exist. How would they? As far as they know, we're not even a bunch of medieval people yet. As far as they can see, we're not landing on the Moon and sending radio signals into space. We're too busy domesticating silkworms, colonizing Scotland, battling King Arthur, inventing matches, changing the Eastern Roman Empire's official language, and sailing to Antarctica in canoes. And they can't see, because they have no reason to look in our direction. None of our signals have reached that star. It will be at least another 1300 years before they even know we exist.  

The signals the survey sought need not be intended for us to be detected. We've been inadvertently filling the space around us with our radio communications out to nearly 100 light years in all directions; we can agree most of these broadcasts are not intended as messages for any neighboring civilization. But any civilization within that sphere would undoubtedly detect these transmission if they point a receiver towards the direction of the Sun. With that in mind supposing an advanced civilization existed around Tabby's Star 1480 years or so ago used such powerful optical-based communications and were only chatting with each other using these means; some of these photons would continue traveling out into space till they reached our instruments. Thus these errant and long traveled signals would still show up on SETI's VERITAS survey during the period of the survey.

[Stargate525]

On 3/24/2016 at 10:52 AM, Streetwind said:

Not necessarily. Planetary atmospheres can theoretically be analyzed by telescopes over vast distances, limited only by the resolution of the telescope. We're doing stuff like that today, already, in a limited fashion. A civilization sufficiently advanced to build "giant megastructures" around their host star might be able to do this from 1500 lightyears away. And Earth's atmosphere is exceedingly unusual; we haven't seen anything like it on any exoplanet yet. The presence of large amounts of biologic activity radically changes it from what you would normally expect for a dead planet. Any sufficiently advanced outside observer should be able to look at Earth from afar and say "yep, that right there is probably a world bearing carbon-based life" with a fairly high confidence.

It's just that they have absolutely no reason to try and communicate with a world that shows signs of life, but zero signs of intelligent life. We just haven't existed for long enough as a technology-based civilization to advertise this fact to the galaxy at large. Life by itself can exist for billions of years without becoming self-aware. It's pointless to try.

Unless the strange light dips of that star are a communication attempt in itself. Which is possible, since (as we see with out current situation) few things are more likely to rouse extreme suspicion in astronomers of another species as a random star exhibiting an unexplainable phenomenon like strong, periodic dimming. You could achieve this by putting an absurdly large sunshield into solar orbit, which repeatedly causes the dimming effect from the eyes of a distant observer everytime it passes by. It's like a giant cosmic billboard screaming "look at me! look at me!". Though unfrtunately this theory fails to explain all of the behavior data that's been gathered so far, so it's unlikely to be a cosmic billboard.

 

If you have a society intent on galactic communication and with power enough to spare, they could broadcast signals at EVERY system that has a planet with a composition friendly to life, and hope for the best.

We've invented spam, why wouldn't they have?

[Rakaydos]

4 hours ago, magnemoe said:

This is interesting as in the effect has to be more than an century old. 
One issue with this being an artificial structure is that it sounds to me being to far from the sun, is it outside the Goldilocks zone?
You would either put something like this as close as possible without burning up the solar panels if you do power generation for beamed power. 
If you use it to power industrial infrastructure putting it in the same orbit as the main planet makes sense for easier travel, you would probably move out once the orbit around the planet is too crowded, keeping in planetary orbit will make travel easier. Putting it farter out would increase size requirements for solar panels with no benefits.

If I recall correctly, the obstructions were estimated to be right in the middle of the F-class star's (brighter than our G class sun) goldilox zone.

[fredinno]

On 3/24/2016 at 9:12 PM, Findthepin1 said:

59 minutes ago, Rakaydos said:

If I recall correctly, the obstructions were estimated to be right in the middle of the F-class star's (brighter than our G class sun) goldilox zone.

What does this mean?

Then I doubt this is a signal from aliens or dyson sphere. Those would be placed as close as possible to save costs and increase efficiency.

 

[magnemoe]

13 hours ago, fredinno said:

Then I doubt this is a signal from aliens or dyson sphere. Those would be placed as close as possible to save costs and increase efficiency.

 

Depend on need, if this is to power habitats or industry it makes plenty of sense to put this in the planets orbit rather than beam the power out. You are chewing up asteroids anyway so larger solar panels is not an huge issue and you started this way. 
Yes this would put everything in one orbit who we are lucky enough to see. 

[Stargate525]

21 hours ago, fredinno said:

Then I doubt this is a signal from aliens or dyson sphere. Those would be placed as close as possible to save costs and increase efficiency.

It wouldn't increase efficiency if they needed to burn several thousand dV to get down to the lower orbit. If they built the panels in the orbit of an asteroid belt or something, you save on logistics.