So
I was reading about this star named KIC8462852. It sits out there some
454 parsecs from our cool blue home. A parsec, which is a unit of
distance and not a measurement of time regardless what my sister’s
boyfriend
Harrison Ford says, is around 3.25 light years. So that puts this star
1,476 light years away. That means that if you had planned to arrive
at KIC8462852 today, and could travel at the speed of light, you would
have had to leave Earth in 540 A.D. But don’t
wait up for news that Romans have arrived at KIC8462852, because it
seems that Emperor Justinian didn’t invest in their space program back
then but preferred instead to spend Rome’s treasury waging war on the
Ostrogoths. I guess it paid off; the Ostrogoths
lost.
Even though we
won’t be visiting KIC8462852 any time soon it stills holds interest.
You see KIC8462852, also known as Tabby’s Star – named after a Yale
researcher - has been getting dimmer.
So what’s the big deal Mark? Nothing last forever. Eventually all stars will get dimmer until the just fade away right?
Right, sure, maybe. But KIC8462852 dims and then brightens back up.
But
Mark, isn’t this dimming and then brightening back up the behavior that
observers use to determine that a star has planets orbiting it? A
planet goes by and the star dims, then the planet moves on and the
star’s light returns to normal?
Yes,
but most stars dim less than 1% when that happens. Tabby’s Star dims
20%, and there is no pattern to the dimming as there would be when an
object passed between it and us in an orbit.
Okay, but maybe it’s something besides a planet. Could there be something else that would cause this behavior?
There
is speculation. Maybe a huge cloud of space junk/dust. It floats by
and really, really dims the star, and then moves on. Or perhaps it’s
something some scientist call comet swarms, breaking apart (and
you thought bees were bad). But infrared observations show there is no
cloud of dust and a reexamination of the data suggests that comet
swarms were far too unlikely.
Okay, so what is causing Tabby’s Star to fade and return?
Another idea began to orbit those who were studying this star; mega-structures.
Wow, that’s amazing! Wait…what’s a mega-structure?
A mega-structure is something that is very, very large and is built by
someone. I mean really huge. They are suggesting that someone has
built or is building something the size of the orbit of say Earth.
Maybe
these folks out there by KIC8462852 really like the star but found that
there are no planets orbiting it that fit their definition of
supporting life. So they build one, or a ring in the orbit of where
they want one, or a sphere around KIC8462852 the size
of that orbit, shutting it in.
Is that what is happening?
Probably
not. At one point SETI, the people looking for extraterrestrial life,
pointed their ears at Tabby’s Star and listened for “deliberately
produced radio signals.” They say they found none.
But what
does a “deliberately produced radio signal” from an alien species sound
like? Especially from someone who could build a building the size of
Earth’s orbit?
They
really look for patterns and found none. If we’ve missed it we can only
hope that they’re not asking how the Ostroghths are doing.
So now what?
Tabby’s
Star is acting strangely and no one has a good explanation as to why.
But that’s okay. Scientists know they won’t solve every mystery and
they seem all right with that. They know they are using tools
invented by someone else while standing on the shoulders of those who
came before them, and I believe they hope that someday, someone will
figure out what Tabby’s Star is doing while standing on theirs.
KIC8462852
is in a group of stars somewhere behind the Northern Cross.
Unfortunately it can’t be seen with the naked eye so those scientist
will be our eyes. By the way, who wouldn’t go to a concert if the bands were named Naked Eye, Comet Swarm, and
The Ostrogoths?
Sometimes I wonder why we’re allowed to view things that are impossible for us to
ever have; like twinkling stars or Jennifer Lopez. But I’ve come to the
conclusion that we are disallowed nothing. The fading and
glowing stars are put there to make us look up. To force us to
imagine…well to imagine pretty much anything, including mega-structures.
Someday,
if we don’t quit trying, we’ll visit KIC8462852 and see in person if there is a
giant ring built around it, if comet swarms exist, or if the star has
long ago simply died out. In the meantime enjoy the view, vicariously of course.