I could not glean from the arxiv paper how far away these anomalous stars were from Earth.<p>Assuming c is a hard limit, the ETI would have to be roughly 50 LY away to catch our first signals and send a beacon signal.<p>If instead they observed Earth as a possible life-bearing planet, which could have been made thousands or millions of years ago, then disregard above paragraph.<p>Or maybe they are just generating signals in more than one direction.<p>Or maybe our interpretation of the anomalies needs adjustment.