James Webb observed the chemical composition of a protoplanetary disk. A cool discovery when you learn that rocky planet formation plays a huge role in a planet’s habitability. This is why it is so interesting to follow the evolution of the chemical composition of dust grains during planet assembly. Interpretations by Benoît Tabone, CNRS researcher at the Institute for Space Astrophysics and author of the study published in the journal natural astronomy.
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The James Webb Space Telescope, which we knew would make exciting and important discoveries in the field of exoplanets, recently observed the protoplanetary disk of the star J160532. he has Allows to reveal the chemical composition of this hydrocarbon-rich disc ”explains Benoit Tabone, CNRS researcher atInstitute for Space Astrophysics (Paris-Saclay University). A more interesting find than it seems.
These remarkable results are First glimpse of the James Webb Space Telescope’s capabilities to identify the physical and chemical conditions that prevail in these disks of dust and gas during planet formation “.
Better understanding of planetary births
In fact, we should know he’s here.” Planets are born in disks of gas and dust that orbit young stars The material there clumps to form “protoplanets” that continue to grow by collecting material they encounter in the disk. But the ” Knowledge about this process is still limited, hence the interest in studying it For this, scientists from 11 European countries have gathered in the MINDES federation (Scan Miri mid-INfrared Disk) to study about fifty of these disks, using the Merry instrument aboard the James Webb Telescope. This program aims to Determine the properties of these disks around a variety of stars of different masses and finally derive statistics “.
Yesterday, Thursday, May 11, the Minds consortium published in the journal natural astronomy Results of a study of one of these first protoplanetary disks, which was orbiting the star J160532. This star definitely means nothing to you. Neither do we. but, ” It was clearly not chosen at random This very young star, which was formed about three million years ago, compared to more than four and a half billion years for the Sun for comparison, and is located only 500 light years from Earth, was chosen because ” Its low mass, about five to ten times less than that of the Sun “.
“J160532 may help us better understand how these small habitable rocky planets formed“
To understand this selection of a star quite different from the Sun, it is necessary to know that observations of these recent years have Show that rocky exoplanets are abundant around these “light” stars. These exoplanets also often form in The habitable zone of their star as evidenced by the famous Trappist-1 exoplanet system So it is likely that the protoplanetary disk of J160532 is a precursor to the disk of Trappist-1, which “ It may help us better understand how these small, potentially habitable rocky planets formed “.
The particles were first discovered in a disc
Using the Merry Instrument, James Webb was able to ” Reveal the chemical composition of this hydrocarbon-rich disk If astronomers expect to discover some of the identified molecules, MARI’s observations still reveal some major surprises. By dissecting the infrared light emitted by gas in J160532’s disk, MARI’s instrument has ” It revealed a very large amount of acetylene (C2h2), a simple and highly reactive hydrocarbon molecule Discovering Molecules The hitherto unknown protoplanetary disks also came as a surprise: two other hydrocarbons, benzene (C6h6) and diacetylene (C4h2) already identified “.
Thus, disc J160532 appears to be extremely rich in carbon molecules in the form of a gas, with very little water and carbon dioxide, whereas these two oxygen-containing molecules are regularly detected in other discs. The authors of this study argue that Hypothesis that the solid carbon in J160532’s disk has changed to a gaseous state due to the intense activity of the young star. “.
This means that rocky planets formed from disc dust grains must have ” The mineral composition is low in carbon just like Earth Interesting find since The composition of the Earth’s mantle, rich in silicates, plays a major role in the geochemical activity (volcanoes, tectonic plates) of the planet and therefore in its habitability. “.
To complement these results and improve our knowledge, new observations are planned, again with James-Webb. this time, ” We want to observe the disk at shorter wavelengths in order to detect carbon monoxide, which is a key compound of the disk’s chemistry The Minds Consortium has also submitted an application to the committee that manages observation times for the ALMA observatory, which operates in the millimeter and sub-millimeter range. Unlike James Webb, who “ It gives access to only a small central part of the disk “Alma must allow us.” To observe the configuration of the outer part of the disk, which will help us understand the entire disk “.
