Scientists have gone back to scanning a pulsating star from a distant galaxy in hope of finding laser emissions that could provide more information about it.
The star known as ‘KIC 8462852’ or ‘Tabby’s Star’ was first discovered three and a half years ago. Astronomers were struck by the way it seemingly shined brighter and then dimmed at random.
One such explanation for that was the existence of an ‘alien megastructure’ that was somehow surrounding the star. Since then, the theory has largely been panned after scientists figured out that some wavelengths of light were being blocked but not others.
Tabby’s Star (NASA/JPL-Caltech/R. Hurt (IPAC))‘The new data shows that different colours of light are being blocked at different intensities,’ said Tabetha Boyajian from Louisiana State University, who helped to identify the star’s strange characteristics.
‘Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure.’
But the idea has stuck around, not least because the media has developed plenty of interest in the idea of alien megastructures orbiting distant stars.
We’re looking and listening for signs of alien life (Swinburne)And as such, a team of astronomers led by Princeton student David Lipman, have been looking at it from a different angle. They’re trying to discover whether laser signs are being beamed out from the vicinity of the star by aliens.
‘We analyse 177 high-resolution spectra of Boyajian’s Star in an effort to detect potential laser signals from extraterrestrial civilisations,’ the researchers wrote in their paper, which has been published online.
They say they are looking specifically for continuous laser light more powerful than 24 megawatts – which is within the current technological capacity of humans to produce.
If there are creatures out there using this kind of light to create the pulses coming from this star, then its possible they could be at least as advanced as we are. The team noted a few false positives during their observations of the star.
Tabby’s Star is located 1,470 light years away from Earth (Getty)‘False positives resulting from cosmic ray events were eliminated through a secondary multi-step analysis process,’ they explained.
‘The top candidates from the analysis can all be explained as either cosmic ray hits, stellar emission lines or atmospheric air glow emission lines.’
Even though they haven’t found conclusive proof yet, this work will be ongoing. And it’s not the only initiative combing the stars for signs of alien life.
A system built by the Breakthrough Listen project spotted new fast radio bursts (FRBs) emanating from a ‘repeater’ called FRB 121102 that’s 3 billion light-years away from Earth.
Is life out there? (CSIRO)Normally, FRBs are spotted during a single ‘outburst’ which happens just once. But the repeater called FRB 121102 is the only source of multiple repeated bursts, including 21 detected in 2017.
Scientists cannot explain the origin of fast radio bursts, but have suggested they are produced by neutron stars, supermassive black holes or even technology built by an advanced alien civilisation.
So while there’s no definitive proof of alien communication yet, humans are getting better and figuring how to look and listen for them if they are there.