A look-alike of the Earth near Proxima Centauri – The Republic

FROM TONIGHT’ll look at the sky with different eyes. Because there, in just over four light-years away, it is a very similar planet to ours. In astronomical terms four years light are very few, practically around the corner. And it is there, around Proxima Centauri, the closest star to us, which is a rocky world a little more massive of our Earth. The observations show then that its surface temperature could allow the presence of liquid water. The new planet, called Proxima b, was discovered by a team of astronomers in the field of observational campaign Pale Red Dot conducted in the first months of this year. The discovery, published in Nature, was announced today during a press conference in Garching near Monaco of Bavaria, in the headquarters of the European Southern Observatory (ESO). The announcement confirms rumors circulating in recent weeks, never confirmed nor denied by ESO and therefore had generated a great deal of expectation among astronomers and beyond. It is a very important step in the study of extrasolar planets. Proxima b, the exoplanet is in fact closer to us, and to its similarity to the Earth will be among the first where we will try traces of extraterrestrial life. And maybe, in a not too distant future, it will become the goal of the first attempts of interstellar travel.

A small red dot. Proxima Centauri is located near Alpha Centauri, a yellow star visible to the naked eye in the southern constellation of Centaurus. Proxima, however, is a very faint red dwarf star, invisible to the naked eye, and to be able to see you need a good pair of binoculars or a small telescope. But given its proximity, Proxima has always been an “under special surveillance” by astronomers seeking extrasolar planets. In particular, this star was dedicated a special observational campaign called Pale Red Dot. The name of the project, coordinated by the astronomer London Guillem Anglada-Escudé Queen Mary University, refers to Pale Blue Dot ( “small dot blue”), an affectionate name by which the American astronomer Carl Sagan he had called our Earth. View from space, especially from the most distant probes, our planet looks just like a small blue dot.

With Pale Red Dot, Anglada-Escudé and colleagues observed continuously Proxima Centauri in order to highlight any small perturbation of its motion in space. The presence of one or more planets in fact due to the gravitational perturbations that alter in a periodic fashion the motion of the star. These “fluctuations” in the stellar motion causes small changes in the light of the star because after the famous Doppler effect. Using the ESO 3.6-meter telescope at the La Silla Observatory in Chile, astronomers have thus highlighted the very small “oscillations” in the motion of Proxima Centauri. Since the red dwarfs like Proxima often vary in brightness in a way that could mimic the presence of a planet, the star has also been monitored by other telescopes, so as to exclude from analysis periods of intense variability.

Day after day, the star’s oscillations became more significant, as noted by the same Anglada-Escudé, “I continued to check the signal consistency every single day during the 60 nights of observation of the campaign. the first 10 were very promising, the first 20 were consistent with forecasts and arrived at 30 days the result was almost final, so we started writing the article! “

a world similar to ours? The observations show that the planet, whose mass is 30% greater than that of the Earth, is at a distance of about 7 million kilometers from Proxima. And ‘so close to the star, much closer than Mercury is from the Sun, and it takes only 11 days to make one complete orbit. But as Proxima is much weaker than the Sun, the planet’s surface is not as hot as that of Mercury: astronomers, light coming from the star would be so dim as to allow surface temperatures much milder, even such as to allow the presence of liquid water in the warmer regions. Climatic conditions, studied in two other articles, would then be liable to then place the planet in the so-called habitable range. Given the conditions of formation of the planet, and the very specific conditions of illumination of the planet, it seems, however, that the climate is very different from the Earth, and that of Proxima b there are no real seasons. But enough of what we know about this planet for attracting the attention of scientists. Proxima b will definitely be studied in greater detail even with future instruments, such as the super-telescope E-ELT. And of course it could become the goal of the early visionaries attempts to interstellar travel, such as the Star Shot project. Scenarios of science fiction, but as we seem closer today.

Topics:

ESO

Pale Blue Dot

Proxima Centauri

mercury

exoplanets

solar system

Proxima b

Starring:

Guillem Anglada-Escudé

Carl Sagan