This is an update in my continuing coverage of the mysterious star KIC 8462852 or Tabby's
star for December 27, 2016.
For the full back story, I suggest checking out my other videos on this channel starting
with my first update video from April of this year and my subsequent updates on this star.
At this stage the star is being monitored every night for the expected deep dimming
events first observed by the Kepler Spacecraft.
And while there have been a few false alarms, Tabby's star has remained stable in brightness
since the observations began earlier this year.
And while it's overwhelmingly likely that we're seeing a natural phenomenon, the alien
megastructure hypothesis is still not discounted.
But the natural explanations that are emerging are improving in quality and we seem to be
moving closer to a consensus on what's going on here.
But, there is dissent, more on that in a minute.
But which natural phenomenon is causing it?
Several new theories and papers have emerged that may provide an answer.
According to a recent paper by Jason Wright of Pennsylvania State University, these theories
fall into four general categories.
Category number one are explanations that lie within our own solar system.
Category two are explanations that lie in the interstellar medium between us and Boyajian's
star.
Category three are explanations that lie in orbit around the star and category four are
explanations that involve the star itself.
Category one: The Solar System
To cause the dips in brightness that Kepler observed with KIC 8462852, you need some kind
of material to block the light.
This could be anything, including alien megastructures.
But the location of that material can be anywhere in between us and the star.
One idea is that there is a small, dense cloud of material in the outer solar system orbiting
the sun and passing by and blocking the light from Tabby's star.
While a reasonable idea on its face, this stands out as odd because we've never seen
an analogue of this cloud of material passing in front of any other star in the millions
of observations we've made of the galaxy.
Because of that we have no real reason other than conjecture to suspect that such a cloud
might be lurking out there.
A second possibility is that there is a Kuiper Belt object passing near the line of sight
of the star that happens to be out gassing material, such as Enceladus does with water
or even Io with its volcanoes.
In other words, something spewing material into space.
This would seem unlikely, you'd need a bunch of conditions to be just right for a geologically
active world to exist in the Kuiper Belt.
It would also need to be doing it in a way that's obscuring KIC 8462852.
That's a tall order.
But, as Pluto recently showed us, bodies in the outer solar system can be quite active
and weird stuff does happen in our solar system.
So, this remains a maybe.
A third possibility that hasn't been well fleshed-out is a slow collision of comets
in the Oort cloud releasing the material.
If that's the case, it would probably be obscuring more than just Tabby's star, so it's not a
great solution.
But all possibilities involving our solar system face two serious hurdles.
Boyajian's star lies well outside the ecliptic plane where the vast majority of matter is
congregating.
While it's not impossible to have material outside the ecliptic, it's definitely there,
it does disqualify most material.
The further you are out of the ecliptic, the less stuff there is to block light.
The second problem is that there is some evidence, albeit weak, of potential periodicity in the
material that was causing the dips in brightness that Kepler observed.
In other words we may have seen it pass by multiple times during Kepler's run.
This is to say that there are indicators that the material is orbiting Boyajian's star.
But it's really weak evidence.
More observation is needed to confirm this.
Think of it as hints of being in orbit, not proof.
Category Two: Material in the interstellar medium
The possibility of periodicity also affects any solutions in this category.
If confirmed, it would eliminate any possibilities here.
However, as it stands, it's still possible that some sort of material is passing in deep
space between us and KIC 8462852.
The nature of this material is debated, it could be dust or gas and could be linked to
any number of astronomical phenomena.
One theory even proposed that the material is located in the accretion disc of a black
hole.
However there are problems with all theories in this category for one simple reason: if
it is a cloud of interstellar dust, it's a very strange one of a type we've never seen
before.
We've never seen one create the kinds of dips Kepler observed.
It's not impossible, of course, but it is unlikely.
Unfortunately, with all explanations on the table for Tabby's star, they all seem unlikely.
The only consensus is that whatever this is, it's a very rare event and that's what makes
pinning it down so difficult.
Category Three: Material in orbit around KIC 8462852
If periodicity is confirmed, this becomes the most likely set of solutions.
The problem here is that all of them are really unlikely given what we've observed and because
of that the potential for alien megastructures being the culprit remains on the table.
But as with anything in astronomy, the last explanation you want to jump to is alien activity.
While it's true that we really don't know how common aliens are, the Fermi paradox makes
it safe to assume that aliens are very rare or we would have seen them by now.
It's also important to remember that we know absolutely nothing about alien megastructures
because we've never seen one of those either.
Trying to figure out what sorts of structures a civilization more advanced than our own
would build is purely conjectural.
We can theorize and speculate, but all we can really define with any certainty is that
the megastructures can't defy the laws of physics.
Because of all the uncertainty, megastructures end up being a wide open explanation that
can fit almost any strange phenomenon we observe in the universe.
That's why we have to be very cautious when discussing that possibility.
It's possible, but not a very good explanation for KIC 8462852.
The natural explanations in this category advanced so far range from disintegrating
giant comets to smashed planets.
I've covered these in my previous updates in depth, so check those out for the back
story, but needless to say none of the explanations are very good.
All of them in this class have fundamental problems based on what we've observed.
Category Four: KIC 8462852 itself.
There's been a few explanations so far that pin the origin of the dips on the star itself.
But until now, they haven't been very solid.
Star spots and dim areas of the star haven't really held up to scrutiny as far as the data
we have goes.
But a new paper suggests something more solid.
It presents that Tabby's star is undergoing an internal phase shift that's messing with
the light that it emits.
A group of mathematicians and scientists at the University of Illinois have been conducting
a study and have authored a paper.
They looked at how the dips in brightness mathematically relate to each other.
This is not unusual, patterns can appear in data and you can study that.
Sometimes significant patterns appear.
Known as avalanche statistics it can shed light on how and when natural phenomena occur.
Importantly, it reveals information about phase transitions.
Think of it as the snaps you hear in a stick as you bend it just before it breaks.
The scientists suggest that the small dips in the Kepler light curve are related to the
larger dips in such a way that they are linked.
This is super-important because it's the first real blow to the megastructure explanation.
If the smaller dips are related to the huge dips, then the constraints placed on the alien
megastructure theory shrink in a major way.
At that point, it would appear that the star is to blame and that we've caught it in a
very rare, but very weird situation where stellar flares and internal conditions of
the star are just so that its brightness is being affected in a strange, but entirely
natural way.
Their model seems to be consistent with what's been observed.
Only time will tell if this theory holds up.
But that's not the only paper that's come out recently.
German mathematician Eduard Heindl recently proposed that a specific type of alien activity
would be consistent with what we see at Boyajian's star.
Known as stellar lifting, this conceptual technology would allow a civilization to mine
the resources of their star for raw materials.
This may sound like science fiction, but in reality we can think of relatively straightforward
theoretical ways to lift material from a star and cool it for use using mirrors, localized
heating, and magnetic fields.
Heindl's theory is noteworthy in that it mathematically explains a very strange feature located in
the light curve that has so far not been particularly explainable using natural means.
The feature is unusually smooth and while not impossible comets and dust clouds would
have a hard time creating it.
But then again, just about everything we know about KIC 8462852 tells us that whatever we're
seeing, it's incredibly rare and unusual.
So there you have it, observations of the star are ongoing but the mystery of Boyajian's
star is not yet solved.
My transcript for this video can be found at my blog the Event Horizon, link in the
description below.
You can also find links there to the scientific papers I referenced in this video for people
that want to dig in deep regarding this story as well as regular posts about technology,
interesting articles I find, and just science and technology stuff in general.
Thanks for listening, I am science fiction author and futurist John Michael Godier currently
with a new book coming out in a matter of weeks.
It's called Supermind and I'm happy to finally unveil the cover art by noted space artist
John Kaufmann, link to his website in the description below and be sure to check out
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explorations into the interesting, weird and unknown aspects of this amazing universe in
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