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 live in, there is still a chance that life might exist around Proxima Centauri, Earth’s closest neighbor galaxy.
Astronomer Joao Faria, lead author of the study, said: Posted this month In the Journal of Astronomy and Astrophysics explains in detail 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 takes just five days to complete one orbit around its star.
It is also likely to be “gradually closed,” like the Moon with the Earth, with one face always pointing toward Proxima Centauri. This could cause extreme temperatures and limit the planet’s ability to have a stable atmosphere, Faria said.
But astronomers are excited about the discovery, despite the hostile conditions that may exist on the new planet.
This suggests that the Proxima system may be “full of planets,” said Faria, a researcher at the Institute of Astrophysics and Space Sciences at the University of Porto in Portugal.
It’s also a breakthrough in the way astronomers search for planets around distant stars, he said in an email, which could soon lead to more discoveries.
The new planet will have to be verified by more observations, but Faria and his colleagues say they discovered it in tiny differences in the light of the star Proxima. – 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 light collected by A. A new spectrometer on a very large telescope On top of a mountain in the Atacama Desert in northern Chile – it’s a much more precise instrument than it was used before.
“We are now able, in terms of mechanical precision, to detect such small signals, opening 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 on 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 do not overlap each other’s planets.
And since Alpha Centauri A and B are remarkably similar to the Sun, it’s possible that life may have evolved on their planets or moons – so scientists plan to search for it 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 moves out of its orbit by about 25,000 years (its name comes from the Latin word for “closest”).
Unlike Alpha Centauri A and B, where no verified planets have been found, three planets have already been discovered around Proxima.
However, none of them are believed to be very similar to Earth, because Proxima is an active “bright star” that regularly doses planets with bursts of intense radiation.
It is still possible that life may have evolved on at least one of its planets, astronomer at Barcelona’s Institute of Space Sciences 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 zone of Proxima or the “Goldilocks” region, where it is neither too hot nor too cold – “on the right scale” – relative to the oceans. of water on its surface.
Observations now indicate that there may already be oceans there; And if so, they could replenish the atmospheric gases from repeated Proxima eruptions, he said. The oceans can also act as a barrier to eruptions, and so it is possible that marine life may have evolved.
Anglada-Escudé hopes to find more planets around Proxima Centauri and other stars while improving astronomical instruments and techniques.
“Within a decade, we should be able to directly observe these planets,” he said. “The idea is to look for life, and see if there are any chemicals that can’t be explained by other natural processes across the planet’s spectrum.”