The observations presented here indicate no evidence for persistent technology-related
signals in the microwave frequency range 1 – 10 GHz with threshold sensitivities of 180
– 300 Jy in a 1 Hz channel for signals with 0.01 – 100 Hz bandwidth, and 100 Jy in a 100
kHz channel from 0.1 – 100 MHz.
These limits correspond to isotropic radio transmitter powers of 4 – 7 * 10^15 W and 10^20 W
for the narrowband and moderate band observations. These can be compared with
Earth’s strongest transmitters, including the Arecibo Observatory’s planetary radar (2 *
10^13 W EIRP). Clearly, the energy demands for a detectable signal from KIC 8462852
are far higher than this terrestrial example (largely as a consequence of the distance of
this star). On the other hand, these energy requirements could be very substantially
reduced if the emissions were beamed in our direction. Additionally, it’s worth noting
that any society able to construct a Dyson swarm will have an abundant energy source, as
the star furnishes energy at a level of ~10^27 watts
