California, United States
In 2016, the discovery of Next b, a planet similar to Earth which orbit the closest star Sun It occupies the cover of the journal Nature. Two years later, Nature reported new findings: a supertierra at least 3.2 times the size of Earth and orbiting Bintang Barnard.
He has used observations from seven different instruments which for 20 years have taken 771 measurements, the amount of information that is "very large", Ribas stressed.
This discovery was made possible thanks to one of the largest international observation campaigns in history, where telescopes around the world have carried out around 800 measurements, "a large amount of information collected over more than 20 years," Ignasi explained. Ribas, from the Catalonia Space Studies Institute (IEEC-CSIC), and who has led international collaborations.
"All of this data has enabled us to characterize planetary systems that orbit Barnard", the second system closest to us and where, furthermore, "we don't rule out the possibility of more planets," the researchers said.
But what about this system? This newly discovered planet depends on the Barnard star, a red dwarf between 7,000 and 10,000 million years, "almost two times older than the Sun", relatively inactive and the fastest of the night sky.
A frozen world
Barnard b, baptized in honor of his hostess, needed around 233 days to orbit the star and, even though it was relatively close (at 40% distance from Tierra del Sol), it was a cold and dark world that could be around -170 degrees Celsius.
"This is a cold world because it receives very little energy from its star: only 2% of what the Earth gets from the Sun", and close to what is called "ice line", the orbital zone around the star in that compound volatiles like water can condense in solid ice. Therefore, "it is very unlikely" that Barnard b had liquid water on the surface, but could not be ruled out that he had it in the soil, Ribas said.
In addition, compared to Proxima b, which is considered a planet with the best chance of saving life outside the Solar System, it seems unlikely that super-earth can contain all forms of life, but "sometimes life finds skilled ways to survive" warned Spanish physicists.
This discovery was made possible thanks to this technique Doppler, one of many methods designed by astronomers to find planets that are impossible to observe directly.
The technique is looking for planets of the effects on the star because, when a planet orbits a star, the gravitational pull causes the star to move too.
"And according to physics, when the light source approaches the observer, the spectrum shifts slightly towards blue and the wavelength is shorter and, when moving away, it moves to red, towards a longer wavelength. Therefore, when we see a vibrating star (approaching and moving away), it can be concluded that there is a planet in orbit, "Ribas said.
Findings from the space planet, which is part of the Red Dots and CARMENES project dedicated to finding planets near the Solar System, has been made possible thanks to measurements of high-precision telescopes from around the world. Among them, famous planet hunters HARPS and UVES spectrographs, both from the European Southern Observatory (ESO).
"HARPS played an important role in this project. Combined data files from other teams with new and overlapping measurements from Barnard stars from various facilities," explained Guillem Anglada Escudé, from Queen Mary University in London. "The combination of instruments is the key to strengthening our results," stressed Spanish astronomers who, in addition, led the discovery of Proxima b several years ago.
And, HARPS, which measures star speed changes caused by extrasolar planets orbiting it, can detect speed variations of even 3.5 km / h (the same level that we use when walking). "This discovery is a significant advance in the search for exoplanets around our star neighbors, in the hope of finally finding one that has the right conditions for home life," concluded researchers at the Institute of Astrophysics of Andalusia and co-authors of the work. , Cristina Rodríguez-López. EFE