The NIROSETI project is based on the assumption that hypothetical communicative extraterrestrials may send out pulsed laser signals in the optical, as well as infrared spectrum. Near-infrared offers a possible way for signal transmission since there is a decrease in both interstellar extinction and Galactic background compared to optical wavelengths. The near-infrared bands remain largely unexplored because instruments capable of capturing short pulses of infrared light have only recently become available. The NIROSETI instrument makes use of the 1-meter optical Nickel telescope located at the Lick Observatory in California to search for near-infrared transmissions from extraterrestrial communication or technosignatures. This project was funded by the Bill and Susan Bloomfield Foundation and is based upon a predecessor called Lick Optical SETI instrument, conducted between 2001 and 2006. Professor Shelley Wright leads the team that built and operates the NIROSETI program. The NIROSETI instrument employs a new generation of near-infrared detectors, cooled at -25 °C, that have a high speed response and gain comparable to photomultiplier tubes, while also producing very low noise, and significantly reducing false positives. Its field-of-view is 2.5"x2.5" each, and focuses on detecting short pulsed laser emissions. The NIROSETI instrument is also being used to study variability of very short natural near-infrared transient stars.
Targets
The NIROSETI survey has been designed for observing several thousand objects over a few years, and commenced full operations on 28 January 2016. During a clear night of observations, about 20 to 30 objects are observed. Because infrared light penetrates farther through gas and dust than visible light, this search will extend to stars thousands of light-years away. The initial target sample is mostly main-sequence and giant stars located within 50 parsecs from Earth, drawn from the Breakthrough Listen program target list. The sample of targets also includes 82 galaxies for being the nearest representatives of the five major morphological classes of galaxies, as well as stars that triggered alarms on other targeted SETI surveys. A significant drawback is that the extraterrestrial laser signals would need to be transmitted in the direction of the Solar System in order to be detected.
