Tabby’s Star : The Mystery Of The Alien Megastructure Has Been Solved?
Since a long time, alien megastructures have been a Centre of attraction of many scientists
and amateur astronomers.
One such major attraction was Tabby’s star.
It's bizarre dimming in light event has been a subject of extensive observations.
Informally known as star KIC 8462852, Tabby's Star has been a subject of curiosity and research
in astronomical world for quite a time now, as astronomers tried to determine why it undergoes
random periods of brightening and dimming.
After years of speculation made by astronomers involving scenarios ranging from comet storms
to “alien megastructures, recent discoveries and research with the help of a Kickstarter
campaign that raised over 100,000$, has finally lifted the curtains of mystery.
So, just sit back and relax and watch the video till the end to find out about the possible
explanations of the strangest star in the universe.
In this video we will discuss all the theories that might be responsible for the strange
behaviour of this mysterious star and what the scientists found out?
The science of finding exoplanets has truly has truly taken off in the 21st century with
the transit method leading the way.
When an exoplanet passes in front of its host star, Relative to our line of sight, the star's
light dims for a short period of time.
The transit method is one of the most widely used method for finding exoplanets.
Today we know of thousands of stars with words around then and most of them have been discovered
by the transit method.
While designing a mission scientist are prepared for odd results.
but the results that were found after observing the Tabby's star were nothing like the one,
they had seen before.
They found Tabby’s star flux dimming by a tremendous amount, without any regular repeating
signals.
So, what was causing this anomalous behaviour of Tabby’s star?
The solution for this is much more mundane: Dust, in an entirely new way looks to be the
culprit.
Since its launch in 2009, NASA's Kepler mission has changed the game of observing exoplanets
and outer worlds completely.
Till now, it has observed about 530,000 stars Undiscovered 2600 plus Exoplanets.
Of All these hundreds of thousands of stars one stands out as the most unusual.
KIC 8462852, also known as Tabby’s star or Boyajian’s star, has some of the most
unique properties in the universe: It exhibits a drop of about 25% in its flux, which is
25 times more than what an exoplanet orbiting its star could cause.
Also, it fades slowly over decades, with unusual brightening events and with no infrared emission
(which all the other stars with large flux dips possesses).
Scientists were baffled by these discoveries, trying to solve this puzzle.
The obvious reason of dimming in the light from a star, is a planet.
But in this case, it couldn't be a planet because no planet is large enough to block
that much light from its host star.
Even a planet with an enormous ring system like a super Saturn could not exhibit these
unusual drops in flux, because they would be periodic and exhibit a smooth pattern.
This contradicted the available data.
Astronomers then thought that this could have been a very young star, with a proto-planetary
disk, a lot of planetesimals and a highly dusty environment.
Previously all the stars with large flux dips, had been placed into this particular category.
But this theory had a problem.
Tabby’s star was too old to have a protoplanetary disk!!
Also, it doesn’t exhibit the infrared flux emission that star with protoplanetary disc
should have.
This is why the it was also named as “where’s the flux” star originally.
It was then proposed that it could be a series of cometary events, where they emit large
amounts of dust and ice while falling into the inner portion of the solar system in question.
This phenomenon could explain the short-term flux dips that had been observed.
But this theory, couldn't explain the long-term dimming of the tabby's star.
Tabby’s star has been under observations for over a century, and observations indicate
a long-term dimming in the brightness of the star, which this model couldn’t account
for.
Cometary dust gets blown off within a few months; it would take continuous bombardments
of comets to sustain the drop in flux for over a century.
Many comets in a similar orbit will be required, something which cannot be obtained.
So, what’s the possible explanation for all of this?
This is where we come to our last theory and a one that many conspiracy theorists were
interested in.
The idea and existence of a giant and advanced alien civilisation blocking the light from
the star.
This theory is definitely one of the most popular one and has gained a lot of attention
over the years.
Afterall, when something unexplainable happens in space, some people assume the aliens have
to be behind it.
But we will explore this possibility too.
So, the hypothesis is that an alien civilisation, that is far more technologically advanced
than humans, was constructing some form of alien megastructure around the star, just
like a Dyson sphere.
The concept of Dyson sphere was first proposed by American theoretical physicist Freeman
Dyson.
It is theoretical mega engineering highly advanced piece of technology that encircles
a star and has the ability to capture all the energy of the star, giving an ultimate
solution for living and energy production in space.
As the construction of this megastructure reaches completion, it would block more and
more of light.
Over the past century, the fact that the light from this star had dimmed by such a significant
amount could be explained by an advance in how completed the structure would be.
This idea might seem crazy to some people and compelling and interesting to some.
However, before you get your hopes up this was not the case.
Thanks to the Kickstarter campaign scientist were able to conduct a follow up observation
recently and found out but this hypothesis was wrong.
but what was the reason behind this? why can't it be the aliens responsible for the dimming
of light from tabby star.
Well, unlike science fiction the organisation responsible for finding extra-terrestrial
life or SETI, hasn't been able to observe any extra-terrestrial activity yet and this
was also the case with the mysterious tabby star.
The main reason behind this is that and object like an alien megastructure would be completely
opaque to light, that is no light will be able to pass through it.
This is equally true for things like planets moon or any other solid objects orbiting an
extra-terrestrial star.
In the past three years, Astronomers have observed over 20,000 images in four different
wavelengths from ultraviolet all the way to infrared.
To rule out the possibility of an alien megastructure, observing those dips in flux as they occurred
was the key.
With this, scientists were able to observe these dips at all wavelength.
If these wavelengths were nearly the same, it would suggest that the cause of the dip
in flux was something opaque, like a planet, star, or an orbiting disk or even something
larger in space.
But after studying four different dips in the flux obtained from Tabby’s star data,
the astronomers found that the dimming was much more definite at some wavelengths and
less intense at others.
This was the opposite of something “solid”.
“The new data shows that different colours of light are being blocked at different intensities.
Therefore, whatever is passing between us and the star is not opaque, as would be expected
from a planet or alien megastructure,” said Boyajian, the scientist to first discover
the star.
So, what was actually blocking the light? the blue wavelength of light is preferentially
blocked in all dimming events: from the short-term flux dips to the long-term fading of the star.
And there is only thing that can cause bluer light to be blocked and redder light to be
preferentially transmitted: Dust particles.
Whatever was causing the flux dips and the long-term fading, had a dusty origin.
According to the newly published research paper, and we quote, “This chromatic extinction
implies dust particle sizes going down to ~0.1 micron, suggesting that this dust will
be rapidly blown away by stellar radiation pressure, so the dust clouds must have formed
within months.
The modern infrared observations were taken at a time when there was at least 12.4% ± 1.3%
dust coverage (as part of the secular dimming), and this is consistent with dimming originating
in circumstellar dust.”
This is where all the evidences were pointing to: dust.
But this is somewhat mysterious.
Because as we mentioned before briefly, Tabby’s star was found to be consistent with dust,
which normally indicates a very young star.
But Tabby’s star has been burning in the main sequence since millions of years.
The dust that we see should only last a few months, unless it replenishes itself.
As far as we can speculate there are two possibilities for this: either there's an external dust
ring that has dense dust clouds in it or infalling bombardment events, or there's something external
to the star that leads to this blocking of the starlight.
the decline in the brightness of tabby's star that has been observed since 1890, appears
to continue through the current 2018 data.
But this decline isn't steady.
There are shorter dips lasting a day or less superimposed on top of them and there are
long period dips lasting for months.
It's definitely due to dust particles as small as 100 nanometres in size.
Though the astronomers have ruled out the possibility of aliens and highlighted the
case of circumstellar dust as the cause of tabby's star mysterious dimming, they continue
to narrow down the type and case of the dust.
Still many others believe that there might be nothing blocking the star, that it might
be dimming and brightening on its own – a possibility not ruled out by the new data.
Or it could be that the dust could be the reason and is a result of a case of stellar
indigestion.
If a giant gaseous exoplanet, the size of Uranus – were devoured by the star, it could
be the culprit behind the dust.
Centuries ago, this planet might have spiralled into the star which would have caused the
brightening, from which the star is now returning to its original, stable state.
The flux dips we observe, then, could be due to planetary debris from an earlier disruption,
or evaporation and outgassing of smaller bodies.
But regardless of the mechanism, one thing Is true: the reason behind the dimming of
Tabby’s star is dust.
The wild speculation behind Tabby’s Star may be coming to an end, but the campaign
that led to it signals the beginning of something new in the field of astronomy.
Tabby’s star emphasized the importance of citizen science and contribution of people
in campaigns like this to support more extensive research in astronomy.
What’s the next chapter in the story of tabby’s star?
There is still a big open question of where did all this dust come from?
It cannot be all interstellar dust?
Was a planet devoured by the star?
While the mystery of an alien megastructure might have been solved, Tabby’s star will
still continue to be a mystery.
Let us know what do you think about this mysterious star in the comment section below.
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