The illustration above shows a star behind a shattered comet. Scientists initially believed the strange behavior of the star KC 8462852 was caused by dusty comet fragments that blocked the light of the star, causing it to occasionally dim.

(NASA/JPL-Caltech)

A star that has long puzzled scientists with its strange behavior has suddenly dimmed again, andresearchers worked to observe its odd actions.

On May 19, astronomers noticed than it had been a few days prior, according to a website dedicated to research on the star.

KIC 8462852 has dimmed like this several times in the past, leading some scientiststo believemegastructures created by alien life , according to Science Magazine.

“This is the first clear dip we have seen since 2013 and the first we have ever caught in real time,” Pennsylvania State University astronomer Jason Wright told Science Magazine.

Astronomers first observed strange behavior from the star between 2011 and 2013 , according to NASA. They watched it dim in dramatic ways they'd never seen before and suggestedthe dips in the light were caused by a swarm of comets or fragments of planets and asteroids.

To test these theories, the researchers used infrared light to observethe star. If aswarm of comets was causingKIC 8462852 to dim, there would be an excess of infrared light around it and the bits of rock would glow at infrared wavelengths. But the scientists found no excess of infrared light, which made both of those theories unlikely.

Researchers have also suggestedthe star ate one of its own planets within the last ten millennia, which caused it to shine more brightly, and now it has begun to dim , according to Smithsonian.

Currently, scientists are working to organize and catalog observations of KIC 8462852 from observers worldwide in an effort further their understanding of the star, according to the research site.