Data from: A Search for Technosignatures Around 11,680 Stars with the Green Bank Telescope at 1.15–1.73 GHz

This dataset describes candidate signal detections obtained at the Green
Bank Telescope in 2020–2023 and processed with the UCLA SETI data
processing pipeline. We conducted a search for narrowband radio signals
over four observing sessions in 2020–2023 with the L-band receiver
(1.15–1.73 GHz) of the 100 m diameter Green Bank Telescope. We pointed the
telescope in the directions of 62 TESS Objects of Interest, capturing
radio emissions from a total of ∼11,680 stars and planetary systems in the
∼9′ beam of the telescope. All detections were either automatically
rejected or visually inspected and confirmed to be of anthropogenic
nature. We also quantified the end-to-end efficiency of radio SETI
pipelines with a signal injection and recovery analysis. The UCLA SETI
pipeline recovers 94.0% of the injected signals over the usable frequency
range of the receiver and 98.7% of the injections when regions of dense
radio frequency interference are excluded. In another pipeline that uses
incoherent sums of 51 consecutive spectra, the recovery rate is ∼15 times
smaller at ∼6%. The pipeline efficiency affects calculations of
transmitter prevalence and SETI search volume. Accordingly, we developed
an improved Drake figure of merit and a formalism to place upper limits on
transmitter prevalence that take the pipeline efficiency and transmitter
duty cycle into account. Based on our observations, we can state at the
95% confidence level that fewer than 6.6% of stars within 100 pc host a
transmitter that is continuously transmitting a narrowband signal with an
equivalent isotropic radiated power (EIRP) > 1013 W. For stars
within 20,000 ly, the fraction of stars with detectable transmitters (EIRP
> 5 × 1016 W) is at most 3 × 10−4. Finally, we showed that the UCLA
SETI pipeline natively detects the signals detected with AI techniques by
Ma et al.