'Alien Megastructure' Star Keeps Getting Stranger
By
If intelligent aliens actually do
live around Tabby's star,
astronomers are determined to find them.
The Breakthrough Listen initiative,
which will spend $100 million over the next
10 years to hunt for signals possibly produced by alien civilizations, is set to begin studying Tabby's star with the 330-foot-wide (100 meters) Green Bank Telescope in West Virginia, project team
members announced Tuesday (Oct. 25).
"The Green Bank Telescope is
the largest fully steerable radio telescope on the planet, and it's the
largest, most sensitive telescope that's capable of looking at Tabby's star
given its position in the sky," Breakthrough Listen co-director Andrew
Siemion, who also directs the Berkeley SETI (Search for Extraterrestrial
Intelligence) Research Center at the University of California, Berkeley, said
in a statement. [13 Ways to Hunt Intelligent Alien Life]
By surrounding their star with
swarms of energy-collecting satellites, advanced civilizations could create
Dyson spheres. [Read the Full Dyson Sphere Infographic Here.]
Credit: by Karl Tate, Infographics
Artist
"We've deployed a fantastic new SETI instrument that connects to that
telescope, that can look at many gigahertz of bandwidth simultaneously and
many, many billions of different radio channels all at the same time so we can
explore the radio spectrum very, very quickly," Siemion added.
The observations will take place for
8 hours per night for three nights over the next two months, with the first
observations set to take place Wednesday (Oct. 26), project
team members said.
Tabby's star, officially known as
KIC 8462852, lies about 1,500 light-years from Earth. Observations by NASA's
Kepler space telescope showed that the star dimmed dramatically several times
over the past half-decade or so, at one point by a whopping 22 percent.
These occasional brightness dips — which were first reported last year by
a team led by Yale University postdoc Tabetha Boyajian (hence the star's
nickname) — are far too substantial to be caused by an orbiting planet,
astronomers have said.
So researchers have offered up a
number of alternative explanations for the dimming to date. Perhaps a cloud of
comet fragments periodically blocks the star's light, for example, or maybe
some unknown structure in the depths of space between Earth and Tabby's star is
responsible.
It's even possible that the
brightness dips are caused by an "alien megastructure" — an
enormous collection of energy-gathering solar panels, for example.
Astronomers
have stressed that the megastructure hypothesis is a long shot, but long
shots shouldn't be dismissed out of hand, Breakthough Listen team members said.
"I don't think it's very likely
— a one-in-a-billion chance or something like that — but nevertheless, we're
going to check it out," Dan Werthimer, chief scientist at Berkeley SETI,
said in the same statement. "But I think that E.T., if it's ever discovered, it
might be something like that. It'll be some bizarre thing that somebody finds
by accident … that nobody expected, and then we look more carefully and we say,
'Hey, that's a civilization.'"
A number of other research teams
have already searched for signals coming from Tabby's star, and all of those
searches have come up empty
so far.
Siemion, Boyajian and astronomer
Jason Wright, who's based at Pennsylvania State University, will discuss the
planned Tabby's star observations during a video chat from the Green Bank
Telescope site on Wednesday at 4 p.m. EDT (2000 GMT). You can watch it live
here:
