Newly
analyzed observations by NASA's planet-hunting Kepler space telescope
show that the star KIC 8462852 — whose occasional, dramatic dips in
brightness still have astronomers scratching their heads — has also
dimmed overall during the last few years.
The steady
brightness change in KIC 8462852 is pretty astounding," study
lead author Ben Montet, of the California Institute of Technology in
Pasadena, said in a statement. "Our highly accurate measurements
over four years demonstrate that the star really is getting fainter
with time," Montet added. "It is unprecedented for this
type of star to slowly fade for years, and we don't see anything else
like it in the Kepler data."
These brightness dips are too significant to be caused by an orbiting planet, so scientists began suggesting alternative explanations. Perhaps a planet or a family of orbiting comets broke up, for example, and the ensuing cloud of dust and fragments periodically blocks the star's light. Or maybe some unknown object in the depths of space between the star and Earth is causing the dimming.
The brightness dips are even consistent with a gigantic energy-collecting structure built by an intelligent civilization — though researchers have been keen to stress that this "alien megastructure" scenario is quite unlikely.
Montet and Simon said they don't know what's behind the weird behavior of Tabby's Star, but they hope their results, which have been accepted for publication in The Astrophysical Journal, help crack the case eventually.
"It's a big challenge to come up with a good explanation for a star doing three different things that have never been seen before," Montet said. "But these observations will provide an important clue to solving the mystery of KIC 8462852."
Even the folks at SETI are now focusing more attention on this strange beast in the sky!
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