L 98-59 is a red M dwarf very close to the Sun with many rocky exoplanets. They are close James Webb Telescope It is destined to become one of the cornerstones of comparative exoplanetology of terrestrial planets with respect to atmospheric analysis. This system contains the smallest exoplanets discovered to date, and is a sibling to three other planets, one of which may be an oceanic planet.
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planetary system aroundstar L 98-59 returns to center stage with publication in the format Astronomy and astrophysics from the teamAstronomical scientist who uses very big telescope From the European Southern Observatory ( VLT ESO) in Chile to confirm and clarify what we already know about it.
In 2019, . released NASA It was previously announced that this woman lips From constellation South poison Flying, only 35 light years From the solar system, at least three outer planet Telluric, one of which is the smallest known to date. find this star rocky uses the transit method thank you TESS . Satellite (Satellite transit to survey the outer planets) from NASA.
Methods for finding exoplanets have varied widely since the 1990s, and can be classified into two main categories, direct methods and indirect methods. The three main methods are the direct imaging method, the indirect crossover method, and the indirect radial velocity method. © CEA Research
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Vital signatures and habitability, concepts that must be handled with care
Remember that Tess, this eye in a orbit From the noosphere, one of the goals is detection planet terestrial which is close to the size of the ground and is located in the living room. Like most stars in Bima Sakti They are red dwarfs and we want to be able to detect potential biological markers in the near future. atmosphere dr’exoterres could be around them, it’s easy to understand why TESS would check the nearest 1,000 M-type red dwarfs Soleil, that is, those that lie within a radius of less than 100 light-years, about 30 league.
Let’s also remember again that convincingly defining what we might actually call a biosignature is far from straightforward and the fact that an exoplanet is located on Residential area to its parent star or slightly beyond it, nor is it evidence that life could or could not develop there. NS’astrophysicist Frank Celsis, member and lab of CNRSastrophysics de Bordeaux (LAB), explained what happened about it on several occasions in items For Futura, for example on the occasion of discovery TRAPPIST-1.
Measurement of planetary transit of an exoplanet gives us its value orbit, its radius and convinces us that if we also find this exoplanet with Radial speed method, we will be able to get the mass and finally the density, since we already know the radius that defines it voice.
Use a team of astronomers very big telescope from ESO in Chile to illuminate planets around nearby stars similar to those in the inner solar system. This video summarizes what they found in a planetary system called L 98-59. For a fairly accurate French translation, click the white rectangle in the bottom right. The English translation will then appear. Then click the nut to the right of the rectangle, then click “Subtitles” and finally “Translate automatically”. Select “France”. © ESO
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The goal is to describe the atmospheres of rocky exoplanets
team led by Oliver Demangeon, researcher atInstitute of Astrophysics and Space Science from the University of Porto in Portugal and lead author of a new study on L 98-59, was able to implement this strategy by applying Speed radial with espresso (Echelle spectrograph for rocky exoplanets and stable spectroscopic observations(installed on ESO VLT and with its predecessor, Harps Tool)High precision radial velocity planet finder) NS telescope 3.6 meters from La Silla Observatory. The researchers not only determined the masses and radii of the three known exoplanets, but they also had evidence of additional planets.
L 98-59 is a red dwarf, so its planetary system is much more compact than the Sun as shown in the video above. Radial velocity measurements confirmed the presence of the three terrestrial exoplanets discovered by TESS as well as the presence of the smallest known rocky planet whose mass was measured using this method. It is closest to its star and is therefore logically called L 98-59 b. Astronomers describe it as having half the mass Venus. With L 98-59 c, maybe too hot to get water fluid on its surface.
The case of L 98-59d is different. Its density estimate shows that it could be planet loud With a mass consisting of 30% water. But as in the case of L 98-59 b and c, we have no information about the presence or absence of an atmosphere and its nature.
L 98-59 d just entered the stage and was in the living room. But again, no case has proven habitable with abundant liquid water. It all depends on how much water you inherit during formation, and how to retain it later Red dwarf rage Able to erode the atmosphere whose composition and whereabouts are not yet known.
L 98-59e now marks the end of his career nose However, its whereabouts have not been confirmed.
The study of the planets around the star L 98-59 will continue and will continue initially in the future James Webb Space Telescope. L’very big telescope (ELT) de l’ESO, dalam Construction In desert Chile from the Atacama, whose observations will begin in 2027, are particularly promising, explained in a press release from ESO Maria Rosa Zapatero Osorio, astronomer at Dr.astrobiology From Madrid, Spain and one of the authors of the study published today: “ HIRES active toolsELT It could have the ability to study the atmospheres of several planets in the L 98-59 system, thus solving JWST from the earth ».
Olivier Demangon adds that: This system is a forerunner of what is to come. As a society, we’ve been chasing terrestrial planets since the birth of astronomy, and we’re finally getting closer to finding a terrestrial planet in the habitable zone of its star, whose atmosphere we can study. »
