This is an update in my continuing coverage of KIC 8462852 or Tabby's Star for October
7, 2017.
The star is currently at nominal brightness having, at least for now, come out of its
most recent dip.
It's anyone's guess when the next could come, though given how active the short term dips
have been lately I would not be surprised to see more in the coming weeks.
There has been a sort of odd phenomenon going on in the media the last few days that people
have been asking me to address.
Usually, the media is quick to jump to the alien conclusion with a story like this because
it makes for good clickbait headlines.
In fact, I originally started this channel with a video on this star intended to look
at the science of what was going on, what that meant, and then I speculated, within
reason, about what it could be to balance out some of the sensationalist content that
was floating around Youtube at the time.
But I also made sure to leave open all possibilities so long as they were possible and that includes
the activities of alien civilizations.
That remains just as possible today as it was six months ago.
But now we have the opposite effect in the media where the clickbait headline is "mystery
solved".
This has happened to some degree before with this star, where someone releases a paper
that does not provide a complete explanation, which is precisely where we are at right now,
and the media goes nuts thinking it is complete and then goes out claiming the mystery is
solved, only to have the whole thing go out the window a month later when some other development
comes along that changes the landscape.
That's probably going to happen again, and I suspect it will continue that way for years
to come.
So mystery solved?
Not really.
We're still very far from that.
But, I caveat, as I've done throughout the odyssey that is KIC 8462852 that it is highly
likely that this is a natural phenomenon, and I personally favor dust in some strange
circumstance, or group of circumstances, of a type that we simply haven't seen before.
This all stems from NASA/JPL having finally weighed in after taking a look at the star
using the Spitzer and Swift missions, looking at infrared and ultraviolet respectively,
along with visual observations from an observatory in Belgium, link to the press release below.
The press release bolsters recent developments that push the explanation of the phenomenon
towards dust, which in all honesty has been one of the more likely culprits all along,
but it does not address one key aspect of this story: the short term dimming events,
some of which have been really strange.
More on that in a minute.
What they found was that the phenomenon orbits in a roughly 700 day orbital period and dims
less in infrared than ultraviolet.
That screams dust as opposed to larger solid objects.
This is a hit against the alien megastructure concept, at least in the form it was originally
presented; the construction of a Dyson swarm or similar activity.
In that event, you'd expect solid objects that absorb all wavelengths equally.
But it does not kill that idea.
If this star goes into another dip of 18-22 percent, especially like the day 792 event
in the Kepler data, and it turns out to be solid, we will be in very different territory
and it must be noted that the observations behind this press release were not taken during
an event of that magnitude occurring.
Really, this press release is based on the recent Meng and colleagues paper that I covered
in the last update.
In short, they conclude from the ultraviolet measurements that the dust must be very small,
but still larger than dust you find in the interstellar medium.
If this is the explanation, it basically has to be this way.
Dust smaller than a certain size would tend to get blown out of the star system pretty
quickly.
Dust larger than a certain size would uniformly block all wavelengths of light.
Add that with the strong signal in ultraviolet, and the shoe seems to fit for dust.
But this only affects the long term dimming trend as no short term dips were occurring
during the observations, and bear in mind the short term dimming events, especially
the larger ones, were what put this star on the map in the first place.
The long term trend was a later discovery.
That represents an Achilles heel here because while it tells you about how the dust is during
a non-dip period, it doesn't tell you how it acts during a dipping event, though in
fairness data from the Boyajian team on the recent short term dips does also seem to suggest
dust.
But, then you're left with figuring out why the dust clouds are so uneven, or whether
something changes in the profile during a major dip such as day 792 from Kepler.
This brings into play a compound answer to the mystery, that swarms of comets are involved,
and may actually be the source of the dust itself, perhaps tossed into the system en
masse by a red dwarf that is known to be nearby.
The problem though is that the dips in Kepler don't really fit the profile of exocomets
based on an exocomet study done by S. Rapport and colleaguesu using the Kepler data, link
below.
Another problem are those very deep long-term dips of 18-22 percent seen by Kepler, and
generally weak infrared emissions overall, at least as far as what's publicly out there
on that.
We really need to see more of those and get some spectra before we can start talking about
the mystery being solved.
As far as an alien civilization goes, as I said before that has never been likely.
It's an explanation that you can form fit to whatever you see, aliens of the gap.
And that makes it problematic from the start.
That said, megastructures aren't the only thing aliens might build.
If they wanted to mine a system for raw materials, they may well kick up a lot of weird dust.
But this is speculation, so much more study of this star is needed before we get anywhere
close to that conclusion.
So in short, we now have the best partial explanation yet as far as natural explanations
go based on some new and welcome data, but once again, like all other explanations it
has flaws and covers only part of the phenomenon.
And, if the history of the study of this star is any indicator, this star loves throwing
wrenches into the works and this all may look very different in a month or two.
Thanks for listening!
I am science fiction author and futurist John Michael Godier currently wondering what any
eavesdropping alien civilization thinks of our clickbait headlines, the humans spotted
us!
wait ... and be sure to check out my books at your favorite online book retailer and
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