A new advance in analytical calculations has just improved the chances of finding extraterrestrial intelligences in our galaxy, according to a team from the University of Manchester.
In a study published today in Monthly Notices of the Royal Astronomical Society, the researchers present a reanalysis of existing data that dramatically broadens the search for extraterrestrial intelligences (SETI). This milestone translates into an increase of a factor of 200 of the stars analyzed: from 1,400 to 280,000 stars.
Research results suggest that less than 0.04% of star systems have the potential to host advanced civilizations with radio technology equivalent to – or slightly more advanced – than humans in the 21st century.
In addition to improving the limits for nearby stars, the team set limits for the more distant stars for the first time, with the cap that any potential life form inhabiting the galaxy’s borders would need even more powerful transmitters to be detectable.
Analysis, the researchers say, can only locate intelligent, technologically advanced civilizations that use radio waves as a form of communication; for example, they could not detect “simple” life or non-technological civilizations.
The team, which is made up of Master’s student Bart Wlodarczyk-Sroka and his advisor, Professor Michael Garrett at the University of Manchester in the UK, and Dr Andrew Siemion, director of the initiative. Breakthrough Listen, has put the best limits on the prevalence of artificial radio transmitters, called techno-signatures, in the Milky Way.
The prevalence of extraterrestrial intelligences
Reviewing the catalogue produced by the European Space Agency’s (ESA) Gaia spacecraft, which measured distances to more than a billion stars, the researchers recalculated limits on the prevalence of transmitters around additional stars within the fields of view. of the radio telescope. By selecting stars at much greater distances (up to about 33,000 light years) than the original sample of nearby stars, they were able to expand the number of stars studied from 1,327 to 288,315.
Team leader Mike Garrett had always been concerned that SETI searches would not take into account the many other cosmic objects that fall within the range of the sky to which a telescope is sensitive, in addition to the primary target.
Knowing the locations and distances to these additional sources greatly enhances our ability to limit the prevalence of extraterrestrial intelligence in our own galaxy and beyond. We hope that future SETI surveys will make good use of this approach, ”the researcher said in a statement.
“Our results help put significant limits on the prevalence of transmitters comparable to what we can build ourselves using 21st century technology,” added Wlodarczyk-Sroka.
‘We now know that fewer than one in 1600 stars up to 330 light-years away is home to transmitters only slightly more powerful than the most advanced radar we have here on Earth. The inhabited worlds with much more powerful transmitters than we can currently produce here must be even rarer. ‘
The large number of stars studied allowed Wlodarczyk-Sroka to set some of the strictest limits to date on the prevalence of radio transmitters in this region of our galaxy. Also, for the first time, the team has been able to do this based on stellar type: the enlarged sample includes not only a wide range of main sequence stars, but also numerous giant stars and white dwarfs.
Source: Manchester University