Search for Nanosecond Near-infrared Transients around 1280 Celestial Objects

Abstract The near-infrared region offers a compelling window for interstellar communications, energy transfer, and transient detection due to low extinction and low thermal emission from dust. We have conducted a search for near-infrared (950–1650 nm) light pulses having durations less than 50 nanoseconds while observing 1280 astronomical objects which include a wide range of nearby stars, clusters, and galaxies. A field of view of 2.″5 × 2.″5 for a duration of at least 300 s was observed for each object pointing. These observations were made using the latest Near-InfraRed Optical SETI instrumentation on the Nickel telescope (1 m) at Lick Observatory. Equipped with two detectors collecting photons coming from the same part of the sky, the instrument is aimed at detecting light pulses coincident between them within nanoseconds, as well as periodic signals. While we report on a few notifications from our system, we believe these events were consistent with the statistical noise of our data. No significant evidence for repeated near-infrared nanosecond pulsed signal was found, given the instrumental limit in sensitivity of 63 ph m −2 ns −1 .