Benji Fields
January 25, 2024
Zoom recording
Abstract:
I outline an archival search for lasers from 2,821 stars, and an active followup investigation into the most interesting technosignature candidate we’ve found. After searching for statistically significant narrow emission spikes, we subjected each detection to a series of tests for false positives, including cosmic rays, bleedthrough from the Th-Ar calibration lamp, night sky airglow lines, and large clusters of emission lines indicative of natural stellar activity. Of the 294 initial detections, 29.3% appear to be natural emission lines, 47.6 % showed visual signatures of cosmic rays and 2.4% were due to calibration lamp bleedthrough. From the remaining 17.7% of candidate observations, we eliminated spikes with linewidths narrower than the instrumental PSF as being the likely product of cosmic rays or other non optical phenomena. This left 14 candidates which survived all filters. Of these 14, a majority are ambiguous–but one in particular matches many of the physical characteristics one would expect from an extraterrestrial laser. The candidate did not repeat in any subsequent observations. It also originates from a G0V type star–not generally known for emission line producing activity. I will share the cosmic detective story emerging around this candidate, and alternative/prosaic hypotheses which we’ve examined. These include interference from LiDAR satellites and drones, natural stellar activity, atmospheric phenomena, ground based adaptive optics lasers, as well as outside contamination from a variety of human light sources including LED and Halogen lights. I will also show the results of an optimal extraction test using the PyReduce algorithm, and what it reveals about the candidate. I will outline a future research program which will assess both the candidate’s viability as a technosignature, as well as any natural astrophysical explanations which may emerge in the process. Finally, I will use this as an opportunity to share my own epistemological framework for non-repeating “Wow! Signal”-type candidates: where they may fit into SETI as whole, and an investigative strategy to uncover their origin.