It turns out that Tabby’s Star — the star that has been hypothesized to have an alien megastructure around it — is not alone when it comes to wild fluctuations in its light output. Astronomers at Germany’s Max Planck Institute for Extraterrestrial Physics have found yet another star that experiences its own drops in brightness, although this one may offer a clue as to why it appears to periodically flicker out.
The star, epically-named "EPIC 204278916", is a fairly young, pre-main sequence red dwarf star that’s only about 5 million years old, and is found in the constellation of Scorpius. Because of its young age, it has a debris disk that may one day form into planets, but over 79 days of observation through the Kepler space telescope, researchers found that the star’s brightness would dip by 65 percent for 25 days straight. This implies, as with Tabby’s star, that there is something extremely large in orbit around it — even a large Jupiter-like planet would only cause a 1 percent dip in the star’s brightness.
While none of the explanations for the variations in Tabby’s Star’s brightness have panned out so far, EPIC 204278916 may have an uneven protoplanetary disk that is angled toward Earth so that we see it edge-on. While there could very well be enough matter in such a disk to block more than half of the star’s light, the disk’s height would have to be extremely thick in some places to be able to block enough light to cause the observed effect.
In the meantime, astronomers are keeping an eye on EPIC 204278916, to see if any more light fluctuations occur.