Around one mature star there appears to be a highly unusual mess of objects circling it, which is very difficult to explain. From the Atlantic:
Boyajian, the Yale Postdoc who oversees Planet Hunters, recently published a paper describing the star’s bizarre light pattern. Several of the citizen scientists are named as co-authors. The paper explores a number of scenarios that might explain the pattern—instrument defects; the shrapnel from an asteroid belt pileup; an impact of planetary scale, like the one that created our moon. [...]It is most likely this pattern was caused by an extremely rare set of natural phenomena, but the small possibility that it could be the result of some type of alien ringworld or Dyson sphere is extremely intriguing.
Jason Wright, an astronomer from Penn State University, is set to publish an alternative interpretation of the light pattern. SETI researchers have long suggested that we might be able to detect distant extraterrestrial civilizations, by looking for enormous technological artifacts orbiting other stars. Wright and his co-authors say the unusual star’s light pattern is consistent with a “swarm of megastructures,” perhaps stellar-light collectors, technology designed to catch energy from the star.
If follow-up research does indicate this pattern is caused by something artificial, it would carry two huge implications. The first is that we are not alone in the universe. The second is that there is alien civilization which possesses technology that is thousands or even millions of years more advanced than our own to be able to create something like this.
*image of Kepler from NASA