Blue Flower

It’s a cosmic game of hide-and-seek. A team of astronomers say that the next search for advanced extraterrestrial civilizations should look for stars – or even galaxies – that have vanished without a trace, as anything so unexplainable could only be due to life far more intelligent than us.

https://www.newscientist.com/article/2095785-impossible-vanishing-stars-could-be-signs-of-advanced-alien-life/