“This event is challenging our understanding of X-ray outbursts: too short to be an ordinary stellar flare, but too faint to be linked to a compact object,” explains collaborator Sandro Mereghetti, lead author of the paper presenting the results.
Another possibility is that the source is a so-called chromospherically active binary, a dual system of stars with intense X-ray activity caused by processes in their chromosphere, an intermediate layer in a star’s atmosphere. But even in this case, it does not closely match the properties of any known object of this class.
Interesting. I guess an alien source was ruled out due to magnitude of the source. Still, would be interesting to see if there is potentially an underlying communication pattern there.