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Super Earth, hunting for life! The planet LHS 1140 b orbits around a dim red dwarf that are “just” 40 years light from us. Quite similar to the Earth, it is interesting to astronomers because the particular alignment in which it is found compared to its star allows it to study it better than any other extrasolar world potentially habitable.The planet LHS 1140 b

Super Earth, hunting for life! The planet LHS 1140 b

For scientists searching in the heavens other planets similar to Earth – other living worlds – the greatest hope can come from a quiet star too weak to be seen with the naked eye: a quiet lonely red dwarf called LHS 1140, which is only 40 Light years from us, in the southern constellation of Cetus. There, an international group of astronomers has found the world that, though not a twin of the Earth, can be considered a close cousin.constellation of Cetus

Super Earth, hunting for life! The planet LHS 1140 b

The LHS 1140 b is a “super-Earth”, a planet bigger than ours, but smaller than Neptune, that is, the world’s most widely-regarded in our galaxy. Many of the super Terre discovered so far have turned out to be “uninhabitable” mini-Neptune, choked in thick layers of gas.uninhabitable mini-Neptune

Super Earth, hunting for life! The planet LHS 1140 b

This world is different. Big less than 50 percent more than Earth is six times heavier: its dimensions suggest it is a rock and metal ball, perhaps endowed with a subtle atmosphere comparable to that of Earth. Its 25-day orbit takes him ten times as close to its star as ever Earth to our Sun, but LHS 1140 shines so weakly that the planet receives only half the light of our world: just enough, What seems, because on its surface there can be a liquid ocean. Because of its proximity to its star, this alien world could be synchronously rotating with it, eternally showing the same face to its sun just as the Moon does with Earth, leaving the other face in a constant darkness.

It is believed that the planet and star are at least five billion years or about half a billion more years than our solar system. The most important thing is that every orbit brings this temperate and rocky world to pass through the surface of its star that is visible from Earth, in an alignment that allows astronomers to observe the planet better than any other potentially inhabitable world beyond the Our solar system. The top planet’s molecules in transit absorb a fraction of the starlight, forming a light ring around the globe that astronomers can study to understand what’s in its alien air. In the years to come, astronomers will use this and other techniques to look for any biosphere traces on LHS 1140 b, as signs of the presence of oxygen and other atmospheric gasses that on Earth literally constitute the breath of life. LHS 1140 b is the best candidate to look for signs of life in the near future, says David Charbonneau, co-author of the article, an astronomer at Harvard University and director of the MEarth project, a global network of small telescopes that observed for The first time the transit of the planet. (The “M” of “MEarth” stands for “M dwarf”, a technical term that indicates red dwarfs with a mass of 30 percent or less than that of the Sun. These stars are by far the most common variety Of our galaxy and the most suitable for planets.)MEarth

Super Earth, hunting for life! The planet LHS 1140 b

It’s the first time we find a rocky planet that gives us the opportunity to look for oxygen. And that’s exactly what we were looking for. The planet was about to escape the observations. In September 2014, the MEarth telescope group, located in Cerro Tololo’s Chilean Observatory, had captured possible LHS 1140b transit signs. Jason Dittmann, MEarth member, and the lead author of the study was charged with trying to confirm and study the potential planet. The LHS 1140b case grew slowly over the next two years because the MEarth team also collaborated with the second group of astronomers working with the European Southern Observatory (ESO) in Chile, the HARPS instrument, the world’s first spectrograph Hunting planets.HARPS

Super Earth, hunting for life! The planet LHS 1140 b

Instead of searching for transits, HARPS locates the planets through the periodic gravitational oscillations that impose on their stars. The technique, slow but fascinating, allows you to evaluate the mass of a planet. MEarth found a transit event, but only one, and was just a signal from the background noise, so they were not entirely sure it was real, says Xavier Bonfils, the astronomer at the University of Geneva who directs HARPS survey on red dwarf stars and co-author of the study. But they had never reported a false positive, so we considered him a pretty reliable candidate and we started an intense observation campaign. Combining HARPS and MEarth observations, the two research groups had predicted that a transit of the alleged planet would be visible from observers to Hawaii and Australians on 1 September 2016. But that night, bad weather prevented five of the six telescopes from observing the star. Only an observer, the amateur astronomer, and co-author of Thiam-Guan Tan was able to actually observe the transit using a small telescope from the periphery of Perth, Australia. That night, Tan sent MEarth’s team an email that signaled her success: Observed exit from transit to ~ HJD +7633.12. Approximately 5 mm deep; That is to say, following the transit of the planet, Tan had a slight decrease of LHS 1140 equal to just half of one percent: equivalent, he says, to observe the fading caused by the passage of a grain of sand in front To a candle at 400 kilometers distance. With the orbital time of the planet, subsequent observations with MEarth and HARPS quickly improved the estimates of its size and mass, revealing it was a giant, rocky world and really worthy of note.

Super Earth, hunting for life! The planet LHS 1140 b

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Super Earth, hunting for life