Astronomers have found evidence of a third planet around the star closest to the sun, bolstering the idea that planets are common around galactic stars, even some of the smallest.
And while the newly discovered planet is less than half the size of Earth and likely too hot to inhabit, there is still a chance that life might exist around Proxima Centauri, Earth’s closest neighboring galaxy.
Astronomer Joao Faria, lead author of the study, said: Posted this month In the Journal of Astronomy and Astrophysics detailing the discovery. “So it is unlikely that the water is in a liquid state and that the conditions are suitable for life.”
In fact, the new planet is so close — about a tenth of the distance between the Sun and Mercury — that it only takes five days to complete an orbit around its star.
It is also likely to be “tidal closed,” like the Moon with the Earth, with one face always pointing toward Proxima Centauri. This could cause extreme temperatures, Faria said, and limit the possibility of the planet having a stable atmosphere.
But astronomers are excited about the discovery, despite the hostile conditions that could exist on the new planet.
She suggests that the Proxima system could be “replete with planets,” said Faria, a researcher at the Institute of Astrophysics and Space Sciences at the University of Porto in Portugal.
It also represents a breakthrough in the way astronomers search for planets around distant stars, he said in an email, which may soon lead to the discovery of more.
The new planet will have to be verified by other observations, but Faria and colleagues say they discovered it in tiny differences in Proxima’s starlight. – Vibrations caused by the planet’s gravity.
Similar techniques were used to detect the first planet found around Proxima in 2016, and another planet in 2019.
But the latest research used the light collected by A New spectrometer in the very large telescope On top of a mountain in the Atacama Desert of northern Chile – a more delicate instrument than the one used before.
“We are now able, in terms of mechanistic resolution, to detect such small signals, opening up the possibility of finding Earth-like planets around sun-like stars in the not-too-distant future,” Faria said.
Proxima Centauri is the third star in the Alpha Centauri system, which is similar to a single bright star from Earth.
It’s just over four light-years away, or about 25 trillion miles – but despite that vast distance, it’s the closest star system.
The light from its two bright stars, Alpha Centauri A and Alpha Centauri B, can only be seen with the naked eye.
They orbit each other, but are far enough apart that they are believed to not overlap each other’s planets.
And since Alpha Centauri A and B both look remarkably similar to the Sun, it’s possible that life may have evolved on their planets or moons – so scientists plan to search for them using custom space telescope.
On the other hand, Proxima Centauri is a small and very faint red dwarf star that was discovered by telescope in 1915, far from the two main stars of the system.
Technically, Proxima is the closest star to the Sun—about a trillion miles closer than other stars—until it takes its orbit away in about 25,000 years (its name comes from the Latin word for “closest”).
In contrast to Alpha Centauri A and B, where no verified planets were found, three planets have now been discovered around Proxima.
However, none of it is thought to be very similar to Earth, because Proxima is an active “glowing star” that regularly doses its planets with bursts of intense radiation.
It is still possible that life may have evolved on at least one of its planets, astronomer at the Institute of Space Sciences in Barcelona, Guillem Anglada-Escud, said.
He led the team that announced Proxima’s first planet In 2016. The planet was found to be roughly the size of Earth and within the narrow, habitable Proxima zone or “Goldilocks” region, where it is neither too hot nor too cold – “just right” – for the oceans of water on its surface.
Observations now indicate that there may indeed be oceans there; And if so, they could replenish atmospheric gases stripped away by Proxima’s repeated flares, he said. Oceans can also act as a barrier to flares, and so it’s possible that marine life may have evolved.
Anglada-Escudé expects to find more planets around Proxima Centauri and other stars as astronomical instruments and techniques improve.
“Within a decade, we should be able to directly observe these planets,” he said. “The idea would be to look for life, to see if there are chemicals that can’t be explained by other natural processes through the planet’s spectrum.”
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