KIC 8462852, also known as Tabby's star was discovered by a team of scientists led by Tabetha Boyajian from Yale University. Today, it is known as the most controversial star with the biggest mystery surrounding its drastic dimming observed by the National Aeronautics and Space Administration's (NASA) Kepler Space Telescope.

The study, published in a preprint server, indicated that Tabby's star was observed for over a period of four years during which the star dimmed by a definitive 3.4 percent in 1,000 days before dropping to another 2.5 percent in a period of just 200 days.

"We offer no definitive explanation that could explain the observed light curve in this work. The effect could be stellar in nature, although there are no known mechanisms that would cause a main-sequence F star to dim in brightness by 2.5 percent over a few months. The effect could also be caused by a passing dust cloud in orbit around KIC 8462852," the researchers wrote, as reported by International Business Times.

The usual hypothesis of the dimming phenomenon is that there is an eclipse or a cloud of dust but because of its highly irregular activity, that theory was scrapped. To date, many theories have been proposed including the possibility that it may be dimming because of a crowd of comet passing by.

Perhaps the most controversial explanation of all is that maybe Tabby's star is actually an alien megastructure that humans may not be capable of understanding. Unfortunately, the Search for Extraterrestrial Intelligence (SETI) reported last year that there were no alien pulses or signals detected from the star.

"The hypothesis of an alien megastructure around KIC 8462852 is rapidly crumbling apart," said Douglas Vakoch, President of SETI International, as reported by Phys.org. "We found no evidence of an advanced civilization beaming intentional laser signals toward Earth."

Despite the result of the search, many still insist that it may still be an alien structure regardless of whether or not a signal was detected. Who knows? Maybe there are signals but just not the ones that SETI knows of or is able to detect.

For now, Tabby's star remains to be a mystery but existing observations of it will be published in The Astrophysical Journal precisely because it is baffling as it is interesting.