An exoplanet closest to Earth can have an unexpected neighbor. It's a remarkable conclusion by a group of astronomers from the University of Turin, Italy, after discovering signs of a new "candidate planet" around Proxima Centauri, a pale red dwarf located just 4, 2 light years away (in fact, is the closest star to the Sun) and in whose orbit is the Next B, rocky planet, discovered in 2016, very similar to ours, which can be also suitable for living.
But the existence of this new world, however, must be confirmed for the news to be official. If it really was there, it would be called Proxima. The announcement was made on April 12, during a Breakthroug Discuss conference, held at the University of California at Berkeley. "It's just a candidate," said Mario Damaso, of the University of Turin. And it is very important to emphasize it. "
Damaso, along with Fabio del Sordo, the University of Crete and team colleagues, analyzed the observations of Próxima Centauri carried out by HARPS (Search Engineer Planet Speed Radial Speed Searcher, or the Search Engine for High Precision Radial Gears) , installed in one of the European Southern Observatory telescopes in La Silla, Chile. The instrument is designed to observe the small and almost imperceptible movements of the stars when they suffer from the "gravitational retreat" of planets in orbit. Precisely, HARPS data helped, in 2016, to discover Próxima b.
As we know very well, Próxima b orbits its star only in the zone of residence, the exact distance, so that the water can exist in the liquid state of its surface. Closer to it, the water will disappear. Further, it would be frozen.
For three years, scientists are arguing about the possibility that Próxima b is capable of preserving life, as on Earth. But it is still not clear and different opportunities are being considered. For example, it is possible that the exoplanet is "attached" gravitatively to its star and shows (as the Moon does with the Earth) always the same person. In that case, the "living" side of Next B would be extremely hot, and the "night" side is extremely cold. In addition, the intense rockets Proxima Centauri removes can take that alien world into its atmosphere, in which case life will not be possible.
A very cold world
But such debates will not affect Proxima c, if its existence was finally confirmed. In fact, this new world, whose minimum mass multiplied by six times that of the Earth, orbits farther away from the Proxima b star. In fact, it is located on 1.5 astronomical units at the next Centauri (an astronomical unit is equivalent to 150 million kilometers) and is therefore very likely to be very cold. Its average temperature, according to Damaso and Del Sordo, would be 234 degrees below zero.
The great distance between the planet and its star was, without a doubt, one of the factors that made it difficult to detect it. And, about 225 million kilometers, the Próxima c of Próxima Centauri's "gravity retreat" would be extremely weak and difficult to notice. Despite everything, Damaso and his colleagues believe that detection will be confirmed soon. Your data and conclusions have already been sent to the scientific journal and will be published shortly.
The definitive confirmation of the new planet may come from the hand of new observations of HARPS itself, or perhaps those who carry out other similar instruments, or those made by the European mission Gaia, who should be able to detect the new world. In any case, confirming that the star that is closest to the Sun has more than one planet, will be great news for astronomers. The new generation of telescopes will actually have the power and resolution necessary for direct photography.