The closest star may have a second Earth-like planet

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The closest star may have a second Earth-like planet
The closest star may have a second Earth-like planet
Anonim

Planetary scientists have found the first evidence that the closest star to us, Proxima Centauri, has not one, but two earth-like satellites. The results of the observations of scientists were published in the scientific journal Science Advances.

“We recently discovered that our closest neighbor, Prosimy Centauri, has at least one Earth-like moon with relatively mild conditions. 5, 8 times, the scientists write.

Four years ago, Guillaume Anglada-Escudé, an astronomer at Queen Mary University of London, and his colleagues made an amazing discovery - they discovered a small Earth-like planet near Proxima Centauri, a red dwarf from the Alpha Centauri triple system, the closest star to us.

In the past, scientists already suspected that one of the luminaries of this system may have satellites in the form of planets, but before the discovery of the world, which received the name Proxima b, planetary scientists could not find unambiguous traces of their existence.

Initially, the researchers assumed that Proxima b is the closest rocky planet to Earth, most of all similar to Earth in all its characteristics. Subsequent observations made them question this. In particular, many astronomers believe that this world is not suitable for the existence of life due to the restless nature of the red dwarf, on the surface of which flares constantly occur that can destroy the atmosphere of the planets.

New "cousin" of the Earth

Aglada Escudé and his colleagues have uncovered hints of another Earth-like planet around Proxima Centauri using the same methods and data they used when they discovered Proxima b. To do this, they used the so-called radial velocity method. This approach, which allows you to find planets by characteristic shifts in the spectrum of the star, which arise as a result of the gravitational interaction of the star and its satellites.

The strength of these "jitters" in the spectrum depends on the mass of exoplanets and the distance between them and the star. Therefore, this technique is still quite difficult to use to search for those planets that are at a great distance from stars or those whose mass is too small compared to the star. Therefore, it is mainly used to search for planets in the immediate vicinity of red dwarfs, which have a fairly low luminosity and relatively calm nature.

Analyzing data collected by their colleagues during checks on the existence of Proxima b, Aglada-Escudé and his colleagues noticed that there was another set of "jitters" in the spectrum of Proxima Centauri. It was not associated with the existence of an already open planet or with various processes in the bowels of the luminary. This convinced astronomers that they were dealing with another planet.

To test this hypothesis, astronomers carried out another series of observations using the European instrument HARPS, which is installed on the 3, 6-meter telescope in Chile's La Silla Observatory. These measurements confirmed that this planet really exists, and indicated that the authors of the article have discovered the smallest "super-earth" so far, which rotates at a record distance from the red dwarf.

As Escudé and his colleagues note, the discovery of this planet, named Proxima c, is extremely important from the point of view of theories of planet formation. This world lies far beyond the so-called "snow line", the border that separates the formation zones of earth-like worlds and giant planets. The existence of an analogue of the Earth in this area casts doubt on these theories or speaks of extremely unusual conditions for the formation of Proxima c.

In the near future, the authors of the article plan to test all these hypotheses using the ALMA microwave observatory located in the Chilean part of the Atacama Desert. Its measurements will help scientists to clarify the size of the planet, reveal its appearance and climate, and also confirm that it exists.

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