Scientists believed they have SOLVED the "alien megastructure" mystery surrounding strange signals from distant Tabby's Star. Observations of the star revealed it was alternately dimming and brightening - and immediately sparked theories of an alien civilization somehow harvesting the star for energy.
Instead, it appears that space dust might be the culprit. According to a new study published in the Astrophysical Journal, a cloud of cosmic dust may be orbiting the star roughly every 700 days - causing the light from the star to dim periodically.
Observations showed that the star's ultraviolet light was dimming more than its infrared light. Huan Meng, lead author of the study at the University of Arizona, Tucson said:
“This pretty much rules out the alien megastructure theory, as that could not explain the wavelength-dependent dimming.”
The team used two NASA telescopes to watch Tabby's Star (officially known as KIC 8462852) from October 2015 to March 2017 in order to measure the UV and infrared dimming.
“We found that from UV, throughout the visible spectrum, to IR, the star is dimming at every wavelength we monitored,” said Dr. Meng. “It cannot be anything from the interstellar medium. Only microscopic fine-dust screens are able to scatter the starlight in the way characterized by measurements.”
The star is located roughly 1,400 light years away from Earth and has confused astronomers since it was discovered in 2015.