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Post by jandl100 on May 19, 2017 20:24:51 GMT
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Post by MartinT on May 19, 2017 23:14:33 GMT
Oh yes, asteroids or broken up planet were the working theories, I think?
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Post by jandl100 on May 20, 2017 6:16:42 GMT
Well, comet swarms, asteroids, recently engulfed planet, known stellar dynamics -- nothing seems to explain the star's extraordinary behaviour. Something new to be learned here! Some decent spectra during a dimming event could at least rule out for sure some of the ideas and may even point to the answer. If all wavelengths are obscured equally then it's a solid object(s) in the way. An alien magastructure, even. If only some wavelengths are obscured then it's a diffuse material and the actual wavelengths obscured will tell which materials are there doing the dimming. One of the problems is that professional telescope time on large instruments is booked up often years in advance, so some folks are going to have to give up their allotted observing time to make this happen! These dimming events in the past have only lasted a few days, so they'd better get on with it sharpish.  "As of 19.05.2017, a new dip in luminosity has been detected. Additional observations are being coordinated. "At about 4 a.m. this morning I got a phone call that Fairborn Observatory in Arizona had confirmed that the star was 3 percent dimmer than it normally is," Jason Wright said in a live webcast. Several observatories including the Keck telescopes and amateurs observatories are watching and taking spectra of the star." Should be getting some results soon. ____ Background - dips up to 22% in the light output of the star have been observed. As a comparison, if a planet the size of Jupiter got in the way, the dip would only be about 1%. And it would also be regularly periodic as it orbited, which the dimming isn't. The star itself would be about twice as big and powerful as our sun. |
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Post by MartinT on May 20, 2017 10:34:00 GMT
Background - dips up to 22% in the light output of the star have been observed. Explaining that, especially as it's aperiodic, is going to take some thinking. The alien megastructure theory would have to explain the absolutely vast size of the thing, as well as how it could move. How about an orbiting black hole, pulling a warped field and detritus along with it? |
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Post by jandl100 on May 20, 2017 10:46:37 GMT
You would expect that to be hot. And no excess infrared is detected. Which places useful constraints on theories.
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Post by jandl100 on May 23, 2017 8:57:53 GMT
Clearly, I'm the only one here actually interested in this  but here is an interesting article, with a prediction/expectation/hope for what might be about to happen. www.cnet.com/news/kic-8462852-tabbys-boyajians-star-aliens-seti-star-space/Here's an interesting graphic from it.  Brightness data from the last few days, with a surprising (to me) amount of scatter and large uncertainty bars, with a solid curve showing possibly similar behaviour from a previous dimming. If the star is indeed following an obscure or long-duration periodic fluctuation cycle of 750 days then a big dip could be happening soon. |
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Post by MartinT on May 23, 2017 9:17:42 GMT
Yes, I saw a similar plot in a different article here. It's fascinating and the theories are plentiful, but nothing particularly convincing yet. |
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Post by Eduardo Wobblechops on May 23, 2017 9:21:32 GMT
No, not the only one Jerry. :-)
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Post by Chris on May 26, 2017 19:08:56 GMT
No,no your not mate! I'm interested but it's a bit much for my pigeon capacity brain. I'm following this thread as you fellas tend to explain things well.
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Post by jandl100 on May 26, 2017 20:44:35 GMT
OK, so folks are interested. Good oh! Here's a recent article presenting latest ideas about what is causing the weird dimming from this star. www.universetoday.com/135719/new-ideas-mysterious-tabbys-star-gigantic-planet-planet-rings/Ideas include - a large, ringed planet in orbit around the star. The body of the planet itself getting in the way as well as the varying obscuration from a set of rings that would surely put Saturn's to shame. Large clumps of gravitationally associated asteroids are also invoked. - a large cloud in the outer reaches of our own Solar System. The variability of the dimming this causes would be in large part caused by the motion of the Earth as it circles the Sun, so Tabby's Star is seen through different parts of the cloud as we circle round the sun. None of the ideas presented can explain everything that is seen, and no combination seems to satisfy either. Personally I am waiting on the results of spectroscopic observations that are currently being made during the current dimming episode - some really good clues must come out of that! |
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Post by MartinT on May 27, 2017 11:00:38 GMT
I like the stable debris and ringed planet theory. All natural and the diagram is quite persuasive.
The alien megastructure idea involves an intelligence and construction abilities so beyond what we can contemplate that it becomes Clarke's magic at work.
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Post by zippy on May 27, 2017 11:13:16 GMT
I'm not a believer in Dyson Spheres - although possible in theory for a highly advanced civilization, what I rarely see queried is why they'd bother ?
If their problem is lack of space or other resource, it would surely be a better plan to decamp to another suitable system. In fact I suspect at that point in their evolution they would probably have already spread themselves across numerous systems, so it would just be a case of leaving the home world behind..
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Post by Chris on May 30, 2017 19:56:28 GMT
I'm utterly stumped. The Dyson sphere sounds like a human type of solution to a problem and something,as zippy mentions,that further intelligences would be way,way past doing. Another planet there? Surely we'd be able to detect that somehow?
I wonder if it's some kind of chemical reaction we're not familiar with - something akin to our leakage of greenhouse gases?
Utterly fascinating anyway.
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Post by Eduardo Wobblechops on May 31, 2017 9:06:49 GMT
I'm not a believer in Dyson Spheres - although possible in theory for a highly advanced civilization, what I rarely see queried is why they'd bother ? If their problem is lack of space or other resource, it would surely be a better plan to decamp to another suitable system. In fact I suspect at that point in their evolution they would probably have already spread themselves across numerous systems, so it would just be a case of leaving the home world behind.. I think it much more likely that advanced civilisations would download themselves into a virtual reality where anything that can be imagined is possible, and immortality is yours. Who wouldn't? Possibly a reason why we've yet to detect another hi tech civ. |
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Post by Chris on Jun 1, 2017 17:39:54 GMT
A world free of speaker cable and fuse arguements....
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Post by MartinT on Jun 1, 2017 18:02:21 GMT
Yeah, but they'd only end up arguing about the relative quality of dilithium versus tritium for transporter use. Or something.
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Post by jandl100 on Jul 30, 2018 17:20:49 GMT
Astroboffins are searching for Dyson spheres with the recently released data from ESA's Gaia mission which has observed and measured the position of 1 billion stars, and so far the motion of 2 million of those. I gave a bit of a goggle-eyed 'say what?!' when reading "We find that a small fraction of stars indeed display distance discrepancies of the type expected for nearly complete Dyson spheres."  arxiv.org/abs/1804.08351Yes, sure - there are bound to be alternate explainations. But ... who knows! |
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Post by Chris on Jul 30, 2018 17:47:29 GMT
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Post by MartinT on Jul 30, 2018 20:03:27 GMT
So calmly delivered, "a small fraction" of possible nearly complete Dyson spheres!
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Post by jandl100 on Sept 28, 2019 8:02:49 GMT
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but here is an interesting article, with a prediction/expectation/hope for what might be about to happen.
