Akshay Suresh, a Cornell doctoral candidate in astronomy, is leading the Breakthrough Listen Investigation for Periodic Spectral Signals (BLIPSS), which is pioneering the search for periodic signals coming from the Milky Way’s core. As a means of searching for extraterrestrial intelligence (SETI) within our cosmic community, the research aims to identify repetitive patterns.
The software that the researchers created was based on the Fast Folding Algorithm (FFA), which is an effective search technique that is more sensitive to periodic sequences of narrow pulses. The Astronomical Journal published their paper, “A 4–8 GHz Galactic Center Search for Periodic Technosignatures,” on May 30.
Pulsars are natural astrophysical objects that generate periodic signals. However, humans also use directed periodic transmissions for a variety of applications, including radar. Pulsars are rapidly rotating neutron stars that sweep beams of radio energy across the Earth. These signals would be a good way to get someone’s attention across interstellar space because they would stand out from the other non-periodic signals and use a lot less energy than a transmitter that broadcasts continuously.
“Our research illuminates the remarkable energy efficiency of a train of pulses as a means of interstellar communication over vast distances. Notably, this is the first thorough study to conduct in-depth searches for these signals.”
Co-author Vishal Gajjar, a SETI Institute astronomer.
“BLIPSS is an instance of state-of-the art programming as a science multiplier for SETI,” said Suresh. “The Fast Folding Algorithm is introduced to SETI for the first time by our research. An FFA is used in our open-source software to analyze over 1.5 million time series for periodic signals in about 30 minutes.
Blipss detection of a desired periodic spectral signal Left: recreated radio recurrence time information containing 64 ghastly channels of width 391 kHz each. The central channel has been injected with a signal that pulses on a regular basis. Right: radio frequency-period (P) diagram illustrating the central spectral channel’s detection of a signal with P0 = 30 s. At P = 15 s and P = 60 s, respectively, the fundamental signal’s first harmonic (cross) and first subharmonic (plus) frequencies (f0 = 1/P0) are also detected. Credit: The Journal of Astronomy (2023). DOI: 10.3847/1538-3881/acccf0
BLIPSS is a cooperative effort between Cornell, the SETI Establishment, and Advancement Tune-In. By concentrating on the central region of the Milky Way, which is well-known for its dense concentration of stars and the possibility of habitable exoplanets, the project significantly increases the likelihood of capturing evidence of technology from other planets. The focal point of the Smooth Way would likewise be an optimal spot for outsiders to send a signal to contact enormous areas of the world.
On known pulsars, the team tested their algorithm and found periodic emission, as expected. The Breakthrough Listen instrument on the 100-meter Green Bank Telescope (GBT) in West Virginia was used to make larger-scale scans of the Galactic Center. As opposed to pulsars, which discharge across a wide area of radio frequencies, BLIPSS searched for rehashing signals in a smaller scope of frequencies, covering less than one-tenth of the width of a typical FM radio broadcast.
“The blend of these somewhat tight transmission capacities with intermittent examples could be characteristic of purposeful mechanical exercises of shrewd human advancements,” said co-creator Steve Croft, Advancement Listen project researcher. “Breakthrough Listen stores a lot of data, and Akshay’s method gives us a new way to look through that haystack for clues that could point to advanced extraterrestrial life.”
“As of recently, radio SETI has principally devoted its endeavors to the quest for persistent transmissions,” said co-creator Vishal Gajjar, a SETI Foundation stargazer. “Our review reveals insight into the momentous energy proficiency of a train of heartbeats for interstellar correspondence across tremendous distances. Notably, this study is the first comprehensive effort to search for these signals in depth.
More information: Akshay Suresh et al, A 4–8 GHz Galactic Center Search for Periodic Technosignatures, The Astronomical Journal (2023). DOI: 10.3847/1538-3881/acccf0
