The James Webb telescope discovered that the giant planets of the multi -year -old system HR 8799 were formed in the same way as Jupiter and Saturn.
The James Webb Space Telescope detected for the first time in a direct carbon dioxide in a multiplanetary system already studied for the dynamics of planets for some time: HR 8799130 light years from us.
In doing so he provided us one of the clearer direct images so far acquired by extrasolar planetsand confirmed that the giant planets within HR 8799 were formed with a slow process, similar to the one with which “our” Jupiter and Saturn were formed. An analysis of the new observations was published in the scientific journal The Astrophysical Journal.
How is a gassy giant born? HR 8799 is a rather young planetary system: it has formed just 30 million years agoa newborn compared to the solar system that has 4.6 billion years. Comprehends At least four giant planets Which emit large quantities of infrared light: a precious fact that scientists are analyzing to understand how those giants have formed.
The possibilities, for the glimmer, are two: either with the slow construction of solid nuclei that then attract gases, as happened for the giants of the solar system such as Jupiter and Saturn; or through the rapid collapse of the cooling disc of a young star. Understand which of the two models of planetary training be more recurrent It will help to better distinguish the exoplanets of the next observations, but also to understand how “strange” our system is.
Eclipse on command. Of very few exoplanets we have direct images, mainly because they are several thousand times less bright than their stars. Using i coronographers (tools of the James Webb that block the light of the guest star so that the planets can be seen), the scientists of the Johns Hopkins University have been able to concentrate on specific wavelengths of the infrared light they reveal traces of certain gases in the atmosphere of the exoplanets.
«Identifying these strong signatures of carbon dioxide, we have shown that there is a considerable fraction of heavier elements, such as carbon, oxygen and ironin the atmospheres of these planets. Given what we know about the star around which they orbit, this probably indicates that they are formed by growth of the nucleus»Explains William Balmer, who coordinated the study.
The previous ones. The observations also made it possible to identify the innermost planet of the system – HR8799 E, the closest to the star – a confirmation of the sensitivity of the James Webb In observing just visible planets attached to very brilliant stars.
The space telescope had already identified carbon dioxide in the past in an exoplanet (Wasp-39 b), but indirectly: he had succeeded in measuring how the atmosphere of the planet altered the light of his star when he passed on it.
In the future. The new observations will allow you to understand if the objects found around other stars are really giant planets or, for example, brunette dwarfs, missed stars that do not accumulate enough mass to start nuclear merger.
