KIC 8462852, a star in the constellation Cygnus, perhaps better known by its nickname “Tabby’s Star,” captured headlines and the imagination of the world this year after its unexplained changes in luminosity drew a wide range of theories and explanations—from gigantic meteor fields to the work of alien technology. The mysterious heavenly body has now become the subject of renewed astronomical exploration as the US$100 million Breakthrough Listen project, which searching the cosmos for evidence of extraterrestrial life, is determined to get to the bottom of KIC 8462852’s secret that has baffled astronomers.

Slightly larger and hotter than our own sun and located some 1,480 light-years from Earth, Tabby’s Star is perhaps the most unusual star ever observed. Named for Louisiana State University astronomer Tabetha Boyajian, who was the lead author on a paper about its behavior, it first entered the limelight in September 2015, when Boyajian’s study revealed that KIC 8462852 was showing massive unexplained dips in luminosity—by up to 22 per cent at seemingly random intervals. Possible explanations for the phenomenon have ranged from swarms of comets, to rogue exo-planets, to the presence of some kind of vast megastructure built by an advanced alien civilization.

“Everyone, every SETI program telescope, I mean every astronomer that has any kind of telescope in any wavelength that can see Tabby’s Star has looked at it,” said Andrew Siemion, director of the Berkeley Search for Extraterrestrial Intelligence (SETI) Research Center and co-director of Breakthrough Listen. “It’s been looked at with Hubble, it’s been looked at with Keck, it’s been looked at in the infrared and radio and high energy, and every possible thing you can imagine, including a whole range of SETI experiments. Nothing has been found.” (International Business Times)

Further investigation has since revealed that KIC 8462852 has also been fading, and that its total light output has declined by an astonishing 19 per cent over the past 100 years. “Observationally, there is zero precedent for any main sequence star to vary in brightness like this,” said Bradley Schaefer, professor of astronomy and astrophysics at Louisiana State University. “Seeing this star fade by 20 per cent over a century is more than just startling.” (Gizmodo)

In an attempt to get to the bottom of this mystery, the Green Bank Telescope in West Virginia, the world's largest fully steerable radio telescope, will spend the next two months gathering data on Tabby’s Star. The telescope is part of the Breakthrough Listen project, launched in January, which aims to focus the world’s most advanced equipment and cutting-edge technology in a comprehensive sweep of the night sky for signs of alien civilizations. The inexplicable KIC 8462852 is receiving special priority under the initiative.

“The Breakthrough Listen program has the most powerful SETI equipment on the planet, and access to the largest telescopes on the planet,” said Siemion. “We can look at it with greater sensitivity and for a wider range of signal types than any other experiment in the world.” (The Christian Science Monitor)

There are also plans to have China’s recently completed Five-hundred-meter Aperture Spherical radio Telescope (FAST), the world’s largest single-dish radio telescope, listen in on the strange star that has captured the imaginations of the scientific community and the public alike. “The FAST telescope will be absolutely incredible for conducting extremely sensitive searches of Tabby’s Star for evidence of technologically produced radio emissions,” said Siemion. “We are very excited to work with our colleagues in China on conducting SETI observations with FAST, including of Tabby’s Star. Within its frequency range, FAST is the most sensitive telescope in the world capable of conducting SETI observations of Tabby’s Star, and will be able to detect the weakest signals.” (South China Morning Post)

While the resources and technology that have been brought to bear in an attempt to solve the mystery of KIC 8462852 are undoubtedly impressive, astronomers are quick to acknowledge that the odds against finding proof of an alien civilization are extremely high. “I don't think it’s very likely [this is due to an alien superstructure]—a one in a billion chance or something like that—but nevertheless, we're going to check it out,” said chief scientist at Berkeley SETI, Dan Werthimer. “But I think that ET, 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.’” (The Christian Science Monitor)

See more

SETI Tunes Into Tabby’s Star with Radio Telescopes (Astronomy Magazine)
Monster Chinese Telescope to Join Tabby's Star Alien Hunt (Seeker)
‘Alien Megastructure’ Star Update: $100 Million Breakthrough Listen Project May Reveal Tabby’s Star’s Secrets (International Business Times)
Alien signals? Massive radio telescope pointed at 'alien megastructure' star (The Christian Science Monitor)
THE SEARCH IS ON FOR ALIEN SIGNALS AROUND TABBY’S STAR (Universe Today)
China’s giant FAST radio telescope to join hunt for extraterrestrial intelligence (South China Morning Post)
This Might Be Our Best Shot at Finding That 'Alien Megastructure' (Gizmodo)
The Mysterious Star KIC 8462852 (SETI Institute)

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