Wed. Apr 24th, 2024

Technosignatures are any measurable property that may provide evidence of extraterrestrial technology. The search for extraterrestrial intelligence (SETI) is a branch of astrobiology that focuses on finding technosignatures, as their detection would provide evidence for intelligent life beyond Earth.

Traditionally, targeted radio surveys have been the mainstay of SETI research, and many SETI projects currently underway still take place in the radio band.

The newly-proposed technique, the SETI Ellipsoid, is a strategy for technosignature candidate selection that assumes that extraterrestrial civilizations who have observed a galactic-scale event — such as supernova SN 1987A — may use it as a point to broadcast synchronized signals indicating their presence.

Using improved 3D locations for stars from Gaia Early Data Release 3, Cabrales et al. identified 32 SN 1987A SETI Ellipsoid targets in the TESS continuous viewing zone with uncertainties better than 0.5 light-years.

Dr. Bárbara Cabrales from the SETI Institute and the Berkeley SETI Research Center at the University of California, Berkeley, and her colleagues show the SETI Ellipsoid method can leverage continuous, wide-field sky surveys, significantly enhancing our ability to detect potential technosignatures.

By compensating for the uncertainties in the estimated time-of-arrival of such signals using observations that span up to a year, they implement the SETI Ellipsoid strategy in an innovative way using state-of-the-arc technology.

“New surveys of the sky provide groundbreaking opportunities to search for technosignatures coordinated with supernovae,” Dr. Cabrales said.

“The typical timing uncertainties involved are of a couple months, so we want to cover our bases by finding targets that are well-documented over the course of about a year.”

“In addition to that, it’s important to have as many observations as possible for each target of interest, so that we can determine what looks like normal behavior and what might look like a potential technosignature.”

In examining data from the continuous viewing zone of NASA’s TESS mission, covering 5% of all TESS data from the first three years of the mission, the authors utilized the advanced 3D location data from Gaia Early Data Release 3.

This analysis identified 32 prime targets within the SETI Ellipsoid in the southern TESS continuous viewing zone, all with uncertainties refined to better than 0.5 light-years.

While the initial examination of TESS light curves during the Ellipsoid crossing event revealed no anomalies, the groundwork laid by this initiative paves the way for expanding the search to other surveys, a broader array of targets, and exploring diverse potential signal types.

Applying the SETI Ellipsoid technique to scrutinize large archival databases signifies a monumental step forward in the search for technosignatures.

Utilizing Gaia’s highly precise distance estimates, the study demonstrates the feasibility of cross-matching these distances with other time-domain surveys like TESS to enhance monitoring and anomaly detection capabilities in SETI research.

The SETI Ellipsoid method, combined with Gaia’s distance measurements, offers a robust and adaptable framework for future SETI searches.

Astronomers can retrospectively apply it to sift through archival data for potential signals, proactively select targets, and schedule future monitoring campaigns.

“The SETI Ellipsoid method, jointly with Gaia distances, provides a straightforward and flexible method for SETI searches that can be adapted to fit different modern surveys and source events,” the researchers said.

“It can be applied retroactively to look for signals in archival data, as well as propagated forward in time to select targets and schedule monitoring campaigns.”

Civilizations Beyond Earth:

Extraterrestrial Life and Society

“…a fascinating collection of essays examining how humanity might react to extraterrestrials……it remains an essential introduction for anyone interested in SETI, xenobiology and UFOs.”  ·  ForteanTimes