A 1.1 to 1.9 GHz SETI Survey of the Kepler Field: I. A Search for Narrow-band Emission from Select Targets

TL;DR

This paper reports a targeted search for narrow-band radio signals from 86 Kepler stars with exoplanets, finding no extraterrestrial signals and setting upper limits on the prevalence of radio-loud civilizations in the galaxy.

Contribution

The study conducted a comprehensive search for narrow-band extraterrestrial signals from specific Kepler stars, establishing new upper limits on the abundance of radio-loud civilizations.

Findings

No extraterrestrial narrow-band signals detected.

Fewer than 1% of transiting exoplanet systems host detectable radio civilizations.

Limits on the number of Kardashev type II civilizations in the Milky Way.

Abstract

We present a targeted search for narrow-band (< 5 Hz) drifting sinusoidal radio emission from 86 stars in the Kepler field hosting confirmed or candidate exoplanets. Radio emission less than 5 Hz in spectral extent is currently known to only arise from artificial sources. The stars searched were chosen based on the properties of their putative exoplanets, including stars hosting candidates with 380 K > T_eq > 230 K, stars with 5 or more detected candidates or stars with a super-Earth (R_p < 3 R_earth) in a > 50 day orbit. Baseband voltage data across the entire band between 1.1 and 1.9 GHz were recorded at the Robert C. Byrd Green Bank Telescope between Feb--Apr 2011 and subsequently searched offline. No signals of extraterrestrial origin were found. We estimate that fewer than ~1% of transiting exoplanet systems host technological civilizations that are radio loud in narrow-band emission between 1-2 GHz at an equivalent isotropically radiated power (EIRP) of ~1.5 x 10^21 erg s^-1, approximately eight times the peak EIRP of the Arecibo Planetary Radar, and we limit the the number of 1-2 GHz narrow-band-radio-loud Kardashev type II civilizations in the Milky Way to be < 10^-6 M_solar^-1. Here we describe our observations, data reduction procedures and results.