An exoplanet has just been discovered around the red dwarf star Wolf 1069. Located in the habitable zone, it would be a super-Earth and could potentially harbor life!
Since the very first confirmed discovery in 1995, more than 5,000 exoplanets have been identified, thanks to different detection methods. Among them, only about twenty were found to be comparable to the Earth: super-Earths, therefore rocky planetsrocky planets of one massemasse similar to that of Earth, located in the habitable zone of their star. A recent study adds one to the list! Posted in Astronomy & Astrophysics and free to access, it describes the researchers’ new discovery: a planet in orbitorbit around theétoile wifeétoile wife red Wolf 1069b, located at 31 light yearslight years of the earth.
Eternal days or nights on Wolf 1069b!
To find it, the researchers used data from the project Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Echelle Spectrographs, or more simply Carmenes. Collected by the Calar Alto observatory in Spain, the data shed light on the presence of an exoplanet around the star Wolf 1069, unearthed thanks to the radial velocity methodradial velocity method. “When we analyzed data from the star Wolf 1069, we discovered a clear, low-amplitude signal from what appears to be a planet about Earth-mass, said Diana Kossakowski, first author of the study, in an MPIA statement. It orbits the star in 15.6 days at a distance equivalent to one-fifteenth of the separationseparation between the earth and the SoleilSoleil ».
This method consists in observing particular variations in the spectrespectre bright with a star. If it is home to one or more planets, the gravitational influence they exert on them will cause it to fluctuate around a center of mass. From the observer’s point of view, it is as if the planet were moving forward or backward. Then involving a doppler effectdoppler effect in the spectrum, shifting towards the blue (the small wavelengthswavelengths) if it approaches, towards the red (the big ones) if it moves away! This effect is particularly visible in the case of red dwarfs, being not very massive, therefore undergoing all the more the gravitational effects of its planets!
Looking more closely at the data on Wolf 1069b, the researchers realized that it was locked by tidal effects! Just like the Moon, it performs at the same time a turn on itself and a turn around its parent star, so that it always shows the same side! This is called rotation synchronoussynchronous. Thus, it is either day eternally or night eternally on its surface!
Wolf 1069b joins the very selective clan of candidates for the search for biosignatures
According to the researchers, on the star side face, there could be a temperature of at least 23°C. Or even more, depending on the planet’s atmosphere. Because being in the habitable zone for a planet does not mean being habitable, but implies a possibility of containing water liquidliquid. But still it is necessary that a atmosphereatmosphere sufficiently thick prevents cosmic rayscosmic rays coming from the star or the interstellar medium to destroy biomolecules. This can be maintained in the case of a sufficiently powerful magnetic field coming from the dynamo effect, as for our Planet. However, in the event that this magnetic field disappears, so does the atmosphere. This is what happened with the planet Mars!
In the case of Wolf 1069, the atmosphere may well have been preserved, thanks to the nature of the star. Red dwarfs, in addition to being the most numerous stars in the Universe, indeed give off much lessenergyenergy and heat. “As a result, the so-called habitable zone is moved inwards”, continued D. Kossakowski. The newly discovered planet receives only about 65% of the incident radiant power of what we receive on Earth, raising hopes for an atmosphere undestroyed by ventsvents stellar! Wolf 1069b thus joins the very selective camp of nearby and potentially habitable exoplanets! Future studies, in particular thanks to theExtremely Large Telescope (ELTELT) currently in constructionconstruction in Chile, should make it possible to know more. Its inauguration is currently scheduled for 2027.
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