The red dwarf Proxima Centauri, belonging to the star system Alpha Centauri and located at a distance of 4.25 light years from us, has discovered the planet Proxima Centauri b, and it may have liquid water and other conditions to support life. Of the 3.5 thousand exoplanets that have been discovered outside the solar system since 1995, it is the closest to Earth.
Its mass is close to that of the Earth, while its year is ten times shorter. Despite the fact that it is separated from the star only a few million kilometers, it is potentially suitable for the existence of life. The discovery was announced at a press conference of the European Southern Observatory in August 2016 in Germany.
The planet was discovered by the radial velocity method using the HARPS spectrograph of the European Southern Observatory. A large body, revolving around the star, as if shakes it with its gravity - the luminary is either slightly accelerated towards the terrestrial observer, then, on the contrary, moves away from him. In this case, the Doppler shift of the spectrum is observed in the radiation of the star reaching astronomers, which is different for the moments of approach and departure. By determining the period of such oscillations of a star, astronomers find out the periodicity of rotation and the minimum mass of a body influencing it with its gravity.
For the planet Proxima Centauri b, the period of rotation around the star (year) is 11.2 days, and the minimum mass is 1.3 Earth's. A year of 11.2 days means that the planet is closer to the center of the habitable zone. This is possible because Proxima Centauri is a red dwarf with a luminosity 60 times less than the sun. Therefore, all planets with a year lasting from 4 to 15 Earth days are potentially inhabited there.
Proxima is a red dwarf with a surface temperature of 3,000 Kelvin (half that of the Sun), so the planets in its habitable zone are very close to it. Proxima Centauri b lies just 7 million kilometers from the star. Because of this, the gravity of the luminary has long achieved tidal capture - a state in which the rotation of the planet and the star is synchronized by gravitational interaction (as in the Moon-Earth pair).
This means that the planet is always facing the luminary by the same side, where the eternal day reigns. In the other hemisphere, respectively, there is an eternal night. On the border of the illuminated and unlit zones of the planet, an equally eternal sunrise and sunset reigns. Earlier, a number of researchers expressed doubts about the possibility of the existence of a complex life in such unusual conditions by our standards.
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