L 98-59 is a red M dwarf very close to the sun with several rocky exoplanets. They are within reach James Webb Telescope and is destined to become one of the cornerstones of comparative exoplanetology of the terrestrial planets with respect to atmospheric analysis. This system contains the smallest exoplanet detected so far, the sister of three others, one of which may be an ocean planet.
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Planetary systems aroundstar L 98-59 back to the city center with publications in Astronomy and astrophysics from the teamastronomer NS Very big telescope from the European Southern Observatory (the VLT from ESO) in Chile to confirm and explain what we already know about him.
In 2019, NASA has announced that this rouge woman from constellation South Fish fly, only 35 English solar system, has at least three exoplanet telluric, one of which is the smallest to date. This discovery star rocky was made using the transport method and thanks to Tess Satellite (Satelit Survei Transit Exoplanet) from NASA.
Methods for detecting exoplanets have been widely used since the 1990s. They can be divided into two main categories, direct methods and indirect methods. The three main methods are the direct image method, the indirect transit method and the indirect radial velocity method. © CEA Research
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Biological signatures and habitability, concepts that need to be handled with care
Remember that Tess, this eye inside orbit nose ball, is one of its purposes to detect planet terestrial which is close to the size of the earth and which is located in the living room. Like most stars in Bima Sakti is a red dwarf and we want to be able to detect possible biological markers in the near future. atmosphere D ‘exoterres around them may exist, it’s easy to understand why Tess is the closest 1,000 red M-type dwarves to Soleil, that is, those within a radius of less than 100 light years, about 30 parsec.
Let us also remember once again that the determination of what can really be conclusively called a biosignature is not clear and the fact that an exoplanet on sitting room from its host or slightly outside it nor is there any evidence that life there could or could not develop. NS’astrophysicist Franck Selsis, member of CNRS and Laboratoriesastrophysics de Bordeaux (LAB), explained several times what is happening on this topic items for Futura, for example in invention Trappist-1.
Measuring planetary transits for an exoplanet gives us rotation period, its radius and convinces us that if we also detect this exoplanet with radial velocity method, we will have access to the mass and finally the density, since we already know the radius he corrected volume.
A team of astronomers has Very big telescope from ESO in Chile to describe planets around stars in environments that look like those in the inner solar system. This video provides a summary of what they found in a planetary system called L 98-59. To get a fairly accurate French translation, click the white rectangle in the bottom right. The English text should then appear. Then click on the nut to the right of the rectangle, then on “Subtitles” and finally on “Automatically translate”. Select “France”. © ESO
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The aim is to characterize the atmospheres of rocky exoplanets
Team led Olivier 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 with speed radial with espresso (Echelle SP spectrograph for rocky exoplanets and stable spectroscopic observations) operates on the ESO VLT and with its predecessor, the Harp Instrument (Radial speed with high accuracy Planet Finder) ke 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 clues about the existence of additional planets.
L 98-59 is a red dwarf, so the planetary system is more compact than the sun, as shown in the video above. Measurements according to the radial velocity method confirmed the presence of the three terrestrial exoplanets detected by Tess, as well as the presence of the smallest and present-day rocky planet whose mass has been measured using this method. It is closest to the star and is therefore logically called L 98-59 b. Astronomers suggest it as half mass Venus. With L 98-59 c maybe too hot to have water fluid on its surface.
Case L 98-59 d is different. Its density estimate shows that a planet ocean with a mass of 30% water. But as in the case of L 98-59 b and c, we have no information about the existence or otherwise of the atmosphere and its properties.
L 98-59 d has just entered the stage and is in the living room. But then again, there’s nothing in the state to prove it’s particularly livable with an abundance of liquid water. It all depends on the amount of water it inherits during its formation, on its subsequent conservation the anger of the red dwarf capable of eradicating an atmosphere whose composition and whereabouts are currently unknown.
L 98-59 e now shows its end nose but its existence has not been confirmed.
The study of the planets around the star L 98-59 will continue and is already in the future James Webb Space Telescope. L’Very big telescope (ELT) from ESO, in construction in desert Chile from the Atacama and which should start its observations in 2027 is very promising, as stated in a press release from ESO María Rosa Zapatero Osorio, astronomer at the Center d’astrobiology from Madrid, Spain and one of the authors of the study published today: ” HIRES Instruments inELT can study the atmospheres of some planets in the L 98-59 system and therefore JWST from the ground ».
Olivier Demangeon added: “ This system is a forerunner of what is to come. As a society, we have been chasing planet earth since the birth of astronomy, and we are finally getting closer to finding planet earth in the habitable zone of its star, whose atmosphere we can study. »
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