Gonzalo López SánchezSEGUIRMadrid Updated: Save Send news by mail electrónicoTu name *
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In 2016, the team of the Spanish Guillem Anglada-Escudé discovered that there is a planet similar to Earth on the nearest star to the Sun . That discovery sparked an intriguing question: Could it be that there is a world living just around the corner, in astronomical terms? The calculations showed that this exoplanet, named Next b , has a mass of 1.27-fold greater than the mass of the Earth. Also it was found out that it is a world rock tour very close to its star, proxima Centauri, a red dwarf little bright located 4.22 light years away.
The question about if Next b is habitable or not it has yet to be answered, but this week a group of researchers from the University of Geneva (Switzerland), among others, has confirmed the finding of Guillem Anglada-Escudé with a lot more precision . His research is the result of one of the first observations of ESPRESSO (“Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations”), a new instrument mounted in the observatory VLT (“Very Large Telescope”), in the facilities of the European Southern Observatory (ESO), in Chile. Their findings have been published in “Astronomy & Astrophysics”.
“ The result that presented is not new, but important , ” he explained to ABC Ignasi Ribas , a researcher at the Institute of Space Sciences (ICE-CSIC), not involved in the study. “This is the independent confirmation of the finding of the Next b four years ago. It has been done by using an instrument much more powerful than that used by Guillem Anglada-Escudé, in 2016, called HARPS, and the new results are consistent pat”.
can A solar system of proxima Centauri?
astronomers, led by Alejandro Suárez Mascareña, have concluded that the Next b is at least 1,17 land masses. Have confirmed that is within the habitable zone of its star , which means you can have liquid water on the surface because it is neither very far away nor very near it, in relation to the radiation that it emits. In particular, Next b is seven times closer to its star than Mercury is to the Sun , and it just takes to 11.2 days to complete a lap of the star.
artist Rendering of a solar system in the star proxima Centauri (in the center) – Science Advances
in Addition to confirming its mass, astronomers have captured a distortion that makes them suspect that the Next b could have a companion, in an orbit closer to the star, but have not been able to secure it: “If the signal has a source planetary– have explained in a press release, Francesco Pepe, researcher of the University of Geneva and co-author of the work– this planet accompanying to Next b would have less than one-third of the mass of the Earth –that is to say, it would be a bit more massive than Titan–”.
that Is to say, even in the nearest star could have a solar system in every rule. “These stars so small and so cold tend to have planetary systems numerous ,” said Ignasi Ribas. “Maybe Next Centauri is not an exception. In addition, some time ago, other authors proposed the existence of another planet for a long period in the system. It is exciting that our companion star might have a planetary system so rich!”.
“it Is exciting that our companion star might have a planetary system so rich!”When the stars rock
Today, the vast majority of exoplanets have been discovered by the method of transits. is The transits are the small eclipses that occur when the planets “make shadow” to pass in front of their suns and cause tiny drops in brightness of stars that can be detected by the instruments. In addition, the falling level of the brightness and the frequency with which it repeats allows to estimate the size of the planets and the duration of its years, respectively.
But, apart from that, the exoplanets may be detected by means of the radial velocity. Basically, the astronomers measured the pitch that occurs in stars when one or several planets revolve around it. Occurs because both the stars as the planets move around a common centre of mass, and has the advantage that from earth you can measure how it zooms in or zooms out the star in relation with us, just allowing to deduce how are exoplanets of the surrounding area. And it is here where the instrument ESPRESSO has reached an unprecedented precision.
The circular motion of the star allows us to estimate the mass of the exoplanet. When the star is about, in relationship with the Earth, its radiation is shifted towards the blue, and when it moves away, toward the red. That offset allows you to measure your speed and deduce how the planet
“When it was discovered Next b, through the radial velocity method, we measured its mass with an error close to 20%,” he explained to ABC Enric Pallé , co-author of the work and researcher at the Institute of Astrophysics of Canarias (IAC). “Here we have repeated the study, using the same techniques, but managing to measure the mass of the planet, with an error below 10%”.
This increase of accuracy has been achieved because ESPRESSO has improved the ability of other instruments to measure the speeds with which the stars are approaching or receding from us because of their pitching. In fact, the instrument has been able to measure speed of 30 centimeters per second , when a person tends to walk a little more than 100 centimeters per second.
The most relevant of this work is precisely to note that ESPRESSO has that ability, so that “ allow the discovery of many small planets , refining the masses of many other planets, and the investigation of atmospheres of gas giants”, has opined Enric Pallé.
Can there be life in the Next b?
however, even that does not come on stream in the next few telescopes, as the ELT or TMT, or the space observatory WFIRST, will not be able to study the atmosphere of planets as small as the Next b. But, is it really possible to find traces of life there?
“it Is very difficult for any planet around a star M –a red dwarf, smaller and less brilliant than the Sun– it has life on its surface”, explained Enric Pallé. “Those planets theoretically have a temperature that allows the existence of liquid water, but during a large part of their evolutionary history have been subjected to processes that have probably vanished any atmosphere that could exist.”
aerial View of the “Very Large Telescope” at the observatory of Cerro Paranal, in Chile – THAT
Essentially, during his youth, the red dwarfs are much brighter and burn up the planets that are near. “That stellar activity involves flares and many emissions in the ultraviolet and X-ray which is also higher in the youth of the star, but that is maintained throughout the stellar lifetime. What does not happen in stars more massive as the Sun”, has listed Pallé.
But all is not lost. Still, you have to verify that, indeed, the planets around these stars does not harbour atmospheres compatible with the presence of life and it is very possible to find some surprises. “In fact, Next b receives (and has received) a dose of high-energy radiation much higher than that of the Earth,” said Ignasi Ribas. “From a geocentric view, this it might seem that leaves touched of death your possible habitability . But to tell you the truth, we know so little about how life works and in which conditions are created and destroyed that it is too early to make statements categorical”. The only thing that remains is to explore a fascinating neighborhood packed with system solar even in the closest star to the Sun.
