No extraterrestrial laser pulses detected from KIC 8462852
To help evaluate that possibility, scientists searched for brief laser pulses from the distant star, but found none, a report in a paper submitted to The Astrophysical Journal Letters shows.
"The hypothesis of an alien megastructure around KIC 8462852 is rapidly crumbling apart," said Douglas Vakoch, President of SETI International and an author of the paper.
"We found no evidence of an advanced civilization beaming intentional laser signals toward Earth," he explained.
The experiment was coordinated by SETI International, a new research and educational organization devoted to innovative approaches to astrobiology and the Search for Extraterrestrial Intelligence (SETI), including Active SETI, in which intentional signals are sent to other stars to evoke a reply.
On six nights between October 29 and November 28, 2015, scientists searched for pulses as short as a billionth of a second at the Boquete Optical SETI Observatory in Panama, using a 0.5 m Newtonian telescope.
The observatory's relatively small telescope uses a unique detection method having enhanced sensitivity to pulsed signals.
If any hypothetical extraterrestrials had beamed intentional laser pulses in the visible spectrum toward Earth, the Boquete observatory could have detected them so long as they exceeded the observatory's minimum detectable limit.
KIC 8462852 has puzzled astronomers because it shows irregular dimming unlike anything seen for another star.
The anomalous light curve was measured using NASA's Kepler telescope, as part of its search for exoplanets.
However, even though a planet the size of Jupiter would cause dimming of approximately 1%, the dimming observed for KIC 8462852 was far greater – up to 22%.
Just as strange, the dimming didn't follow the regular pattern of a planet orbiting a star, but instead was unpredictable. The best explanation to date is that the dimming may have been caused by cometary fragments in a highly elliptical orbit around KIC 8462852, intercepting starlight at the same time the Kepler mission was observing it. ■
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