It has been thought that one of the planets circling Proxima Centauri, the nearest star to our sun, lies inside what scientists term the habitable zone.
Although Proxima b is 20 times closer to its star than Earth is to the sun, since Proxima Centauri is a colder and smaller star, it receives a comparable amount of energy-heat, and light-than Earth receives from the sun.
This makes the world not too hot and not too cold for any life to survive in the so-called "Goldilocks zone," which implies possible liquid water present on the surface. Scientists equate liquid water with life on Earth, and it has often informed their quest for life outside it.
New research, uploaded in The Astrophysical Journal, has dampened expectations that there might be some suggestion of existence on the surface, with the earth possibly undergoing inhospitable space weather.
Proxima Centauri ejects material onto a nearby planet
For the first time, a team of Australian researchers showed a conclusive link between optical flares and radio bursts on a star that is not the sun. According to a report released Wednesday in The Astrophysical Journal, the discovery was a significant move toward utilizing radio waves from distant stars to explain better the drastic impact of space weather on solar systems outside our own.
Experts say our own Sun regularly emits hot clouds of ionized particles during what we call 'coronal mass ejections. Lead author Andrew Zic, who researched while at the University of Sydney, said our 'habitable zone' is far from the Sun's surface. That means our planet needs to go a relatively long way from these events.
Given the Sun is much hotter than Proxima Centauri and other red-dwarf stars, he said hugely energetic expulsions of ionized gas and radiation called coronal mass ejections leave the stellar atmosphere.
"The Earth has a very powerful planetary magnetic field that shields us from these intense blasts of solar plasma. But given Proxima Centauri is a cool, small red-dwarf star, it means this habitable zone is very close to the star; much closer in than Mercury is to our Sun," said Zic, who is now a postdoctoral researcher at Macquarie University.
"What our research shows is that this makes the planets very vulnerable to dangerous ionizing radiation that could effectively sterilize the planets."
More prone to UV radiation and x-rays?
The results clearly imply that planets orbiting this type of star are probably dosed with stellar flares and plasma expulsions and can undergo extreme atmospheric erosion, making them vulnerable to very powerful X-rays and ultraviolet radiation.
It was probable, Zic said that radio bursts could occur in the sun for different purposes, where coronal mass ejections are normally correlated with them.
However, the likelihood that the detected solar flare and intercepted radio signal from our neighbor were not associated is much less than one chance in 128,000, he said.
This is possibly bad news on the weather forecasting front, Zic said. He mentioned that the galactic most famous stars like the red dwarfs wouldn't be the right stuff to ask about finding life as we know it.
Zic added, though, it was technically plausible for exoplanets - planets beyond our solar system - to have magnetic fields such as Earth's.
Magnetic fields surrounding exoplanets have not been detected yet, the statement said, and discovering these could prove tricky.
"Unless there were gravitational anomalies, Zic said this would not be enough to defend them given the stellar proximity of habitable-zone planets around M-dwarf stars.
Astronomers found Proxima b in 2016 by astronomers. They found its presence again this year. It's one of the nearly 4,000 exoplanets spotted since the 1990s.
Proxima Centauri's measurements were made with the Western Australia CSIRO Australian Square Kilometre Array Pathfinder (ASKAP) telescope, the University of Western Australia Zadko Telescope, as well, as other devices.
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