The well-known Wow! Signal continues to be one of the crucial intriguing candidate radio alerts ever discovered within the seek for extraterrestrial intelligence (SETI). To this day, scientists haven’t defined its origin. The Ohio State College’s Big Ear radio telescope picked up the sign close to the 21-cm hydrogen line at 1420 MHz. It was tantalizing. Nevertheless it lasted solely 72 seconds after which was gone … and has by no means returned.
Scientists searched, and watched, however by no means heard the sign once more. Was it a case of radio interference from Earth? An unknown kind of pure radio sign? Or might it, in actual fact, have been a real sign from an alien civilization? We might by no means know for positive. However astronomers are nonetheless attempting to pinpoint its origin.
Now, the Breakthrough Listen crew is reporting the outcomes of their very own seek for a repeat of the elusive Wow! Sign. They published their new peer-reviewed paper within the September 2022 situation of Analysis Notes of the AAS.
Did the Wow! Sign come from a sun-like star?
The brand new search targeted on the sun-like star 2MASS 19281982-2640123, which lies within the course of the primary detected sign. Furthermore, it’s very like our personal sun, with comparable temperature, radius and luminosity. It’s 1,788 light-years away from Earth within the constellation Sagittarius. Beforehand, astronomer Alberto Caballero had identified the star in 2020 as a doable supply for the Wow! Sign.
The unique Huge Ear radio telescope used two feed horns for listening, one constructive and the opposite unfavorable. Caballero’s crew, utilizing knowledge from the Gaia mission, discovered 38 and 28 Ok- and G-type stars within the horns’ detectability vary, respectively. In the end, the researchers recognized 2MASS 19281982-2640123 as the one sun-like star that in that group.
The Breakthrough Hear crew, nonetheless, used extra superior filtering standards for analyzing the celebrities within the area. They really discovered eight sun-like stars within the area the place the Wow! Sign originated.
Breakthrough Hear used each the Green Bank Telescope (two 30-minute observations) and the Allen Telescope Array (six 5-minute observations). The search targeted on the L-band portion of the radio spectrum (1-2 GHz). Particularly, the crew regarded for slender band alerts, which might be almost definitely to be synthetic. Each telescopes scanned the sky for a interval of 9 minutes and 40 seconds.
New seek for the Wow! Sign: nothing discovered
So, what was the consequence? Sadly, as with earlier searches, the researchers didn’t discover something. As Breakthrough Hear stated:
No technosignature candidates had been discovered, though there stays an abundance of different stars from which the sign might have originated.
Because the paper noted:
Each telescope observations had an overlap of 580 s. Whereas blind searches utilizing radio telescopes have been carried out within the common subject of view wherein the Wow! Sign was first detected, that is the primary time a focused search has been accomplished. No technosignature candidates had been detected.
It’s one other disappointing consequence, however as famous, there are at the very least eight sun-like stars within the area the place the sign might have originated. In the end, future observations might goal a few of these stars.
What about different stars?
Generally, we consider sun-like stars as best targets, since life on Earth advanced with the identical sort of star, our sun. However what about red dwarfs? Considerably, they’re the commonest kind of star in our galaxy, and astronomers have discovered many exoplanets orbiting them, together with rocky worlds like Earth. We don’t but know what the probabilities are for all times to originate on planets round purple dwarfs, however from what we do know thus far, it appears there’s an affordable likelihood. What number of of those stars are within the Wow! Sign listening zone?
Download the data sets from Breakthrough Listen
Backside line: Scientists with Breakthrough Hear simply carried out a brand new search round a sun-like star for the well-known Wow! Sign detected in 1977. Sadly, they heard nothing.
