Akshay Suresh, a doctorate candidate in astronomy at Cornell University, is
leading the Breakthrough Listen Investigation for Periodic Spectral Signals
(BLIPSS), a groundbreaking effort to find periodic signals coming from the
Milky Way's center. The study looks for recurring patterns as a technique to
look for extraterrestrial intelligence (SETI) in the area around our solar
system.
In order to increase sensitivity to periodic sequences of tiny pulses, the
researchers created software based on the Fast Folding Algorithm (FFA), a
powerful search technique. Their research article, titled "A 4-8 GHz
Galactic Center Search for Periodic Technosignatures," appeared in The
Astronomical Journal on May 30.
Radar is one of the many uses for directed periodic transmissions that
people use today. Pulsars, which are fast spinning neutron stars that sweep
beams of radio energy over the Earth, are naturally occurring astronomical
phenomena that produce periodic signals. Such signals would stand out from
the background of non-periodic transmissions in interstellar space, yet they
would use a lot less energy than a transmitter that is broadcasting
continually.
According to Suresh, "BLIPSS is an example of state-of-the-art software as
a science multiplier for SETI." The Fast Folding Algorithm (FFA) is used by
our open-source software to crunch over 1.5 million time series for periodic
signals in around 30 minutes, which is a first for SETI.
Breakthrough Listen, the SETI Institute, and Cornell worked together to
create BLIPSS. By concentrating on the Milky Way's core area, which is
recognized for its high concentration of stars and possibly hospitable
exoplanets, the effort considerably increases the likelihood of discovering
proof of extraterrestrial technology. A beacon placed in the Milky Way's
core would make it possible for extraterrestrials to communicate with
significant portions of the Galaxy.
On known pulsars, the researchers tested their technique, and they were
successful in detecting periodic emission as predicted. The researchers next
looked at a bigger dataset of scans of the Galactic Center made with the
Breakthrough Listen instrument on the 100-meter Green Bank Telescope (GBT)
in West Virginia. BLIPSS searched for repeated signals in a smaller
frequency range, less than one-tenth the breadth of a typical FM radio
station, as opposed to pulsars, which radiate throughout a broad range of
radio frequencies.
According to co-author and Breakthrough Listen project scientist Steve
Croft, "the combination of these relatively narrow bandwidths with periodic
patterns could be indicative of deliberate technological activities of
intelligent civilizations." "Breakthrough Listen captures enormous volumes
of data, and Akshay's technique provides a new method to help us search that
haystack for needles that could provide tantalizing evidence of advanced
extraterrestrial life forms," says Akshay of his technique.
The search for continuous signals has been the main focus of radio SETI's
work up until this point, according to co-author and astronomer at the SETI
Institute Vishal Gajjar. "Our research highlights the astounding energy
efficiency of a series of pulses as a form of interplanetary communication
over extremely large distances. Notably, this research represents the
first-ever thorough effort to carry out in-depth searches for these
signals.
Provided by
Cornell University
