KIC 8462852, also known as Tabby's Star, has dimmed again. Researchers say that it dipped in brightness more dramatically than ever.
Tabby's Star Dims Again
Louisiana State University astrophysicist Tabetha Boyajian, who discovered the star, and colleagues, revealed that the star has dimmed by at least 5 percent and possibly 10 percent.
The scientists said that Tabby's star, also called "alien megastructure star" due to its bizarre behaviors suspected to be associated with an intelligent alien civilization, started to dim on March 16 and then returned to normal.
Boyajian and colleagues said that the dip in brightness was the largest observed dip in the star since 2013.
"On Friday (2018 March 16) we noted the last data taken were significantly down compared to normal," the researchers wrote in their Tabby Star observation blog. "This is the deepest dip we have observed since the Kepler Mission in 2013! WOW!!"
By March 22, the star's brightness increased rapidly and was nearly back to normal but it started to dim again on March 26.
"Today we have some very big news - data taken at TFN last night show the flux is down 5 percent," Boyajian and colleagues reported on March 26. "Looks like we beat the record set just last week on the deepest dip observed since Kepler!"
In 2011, the Kepler Space Telescope observed that the star dimmed as much as 22 percent. Other dimming events also occurred throughout 2017.
Possible Causes Of Tabby Star's Sporadic Brightening And Dimming
A planet that passes between a star and Earth will cause the dimming of the host star by 1 percent or less and at regular intervals. What makes the Tabby's Star different from many others is it dims irregularly, and the dimming occurs at unpredictable intervals and at varying degrees.
What's behind the star's erratic dips in brightness remains a mystery albeit researchers have proposed several theories. One of the most popular ideas is that the star is orbited by alien megastructure such as an array of solar panels that were created by an intelligent extraterrestrial civilization.
A 2017 study suggests that the mysterious dimming could be due to the star devouring a nearby planet. Another idea suggests the dimming is caused by comets. In January, researchers proposed that the dips in the star's brightness are likely caused by interstellar dust.
Researchers continue to observe the star in the hope that new data could finally unveil Tabby's Star's mystery.