Sorry, History Channel Alien Guy, but researchers from Vanderbilt University have discovered evidence that an F-type main-sequence star in the constellation Cygnus is probably not home to an alien civilization slowly enclosing it in a megastructure called a Dyson sphere.
The star in question, known as KIC 8462852 (or Tabby’s star, after Yale University astronomer Tabetha Boyajian), is located roughly 1,480 light years away from the Earth and was found to be home to a series of unusual light fluctuations over a 100-day period.
The uneven, unnatural dips in brightness suggested that large quantities of oddly-shaped objects were passing in front of the otherwise typical star. Previous research had suggested that the data showed a “bizarre light curve” that was “consistent with” a megastructure built by aliens.
Scientists initially suggested that an alien megastructure could explain the strange light fluctuations.
Since then, other researchers have examined Tabby’s star and found no evidence of light signals that would suggest the presence of extraterrestrials building a Dyson sphere. Now, researchers at Vanderbilt and colleagues from Lehigh University, NASA and Germany reported in a new study that there was, in fact, no credible evidence that the star’s brightness was steadily changing.
So caused the dip in brightness? That remains unknown.
Their work, which has been reviewed by peers and accepted for publication in the Astrophysical Journal, follows a January paper from Louisiana State University astronomers which stated that Tabby’s star had dimmed by one-fifth over the past 100 years – which, if true, would be hard to explain naturally, but would be consistent with the alien megastructure hypothesis.
In that scenario, extraterrestrials could theoretically be converting material in the KIC 8462852 system into large-scale structures that have been absorbing an increasing amount of energy from the star for more than a century. The new Vanderbilt-led paper, however, found no evidence that any significant changes had been taking place, and that the causes of the dips in brightness, while still unexplained, are almost certainly due to natural causes and not the work of aliens.
As VU physics and astronomy professor Keivan Stassum explained in a statement, “Whenever you are doing archival research that combines information from a number of different sources, there are bound to be data precision limits that you must take into account.” He and his fellow researchers looked at variations of several other, comparable stars using the same database used by the LSU team, the Digital Access to a Sky Century @ Harvard (DASCH).
They found that “many” of these stars “experienced a similar drop in intensity in the 1960’s. That indicates the drops were caused by changes in the instrumentation not by changes in the stars’ brightness.” Still, the fact remains that something is transiting in front of the star, added study co-author and German amateur astronomer Michael Hippke. Discovering just what that might be and solving this cosmic conundrum will require additional research.
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Image credit: NASA/JPL/Caltech
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