I followed Tabby's Star news for a while (star that showed massive dips, speculation was that it is a dyson sphere being built). Most scientists believe that e

I followed Tabby's Star news for a while (star that showed massive dips, speculation was that it is a dyson sphere being built). Most scientists believe that even if the star is encased in Dyson sphere that there would be excess infrared emissions as the sphere would need to vent heat. It would be hotter than surrounding space and thus visible. They are thus trying to detect such stars with higher mass and IR excess than expected, but so far there are not many candidates.