James Webb manages to capture the image of an exoplanet… full of mysteries

And one more feat for James Webb, the space telescope that combines “scientific firsts” at record speed. James Webb (and the scientists who worked on this observation) managed to recover the “direct” image of an exoplanet! HIP 65426b is a gas giant located 385 light-years from the Solar System and 92 astronomical units from its star (about three times the distance between Neptune and the Sun), which does not prevent it from reaching 1000 degrees at its surface ! Scientists are already constructing several hypotheses to explain these high temperature levels for an exoplanet so far from its star: HIP 65426 b could thus have formed much closer to its star before being ejected “far” by an effect of “gravitational billiards” but it is also possible that the star and the gas giant formed together, one of the stars having devoured most of the available material and leaving no other possible choice for the second object than to become a planet (rather than a second star or a brown dwarf).

James Webb exoplanet

James Webb managed to nab the image of HIP 65426 b, an exoplanet (HIP… HOP, ok, I wouldn’t do that again…). Below and from left to right, the images obtained largely thanks to the coronagraph on board by James Webb: the purple shows the exoplanet seen by NIRCam at 3.00 micrometers, the blue is the same image via NIRCam but this time at 4 .44 micrometers, yellow is the sight of MIRI (11.4 micrometers) and finally red is always the sight of the MIRI instrument at 15.5 micrometers. The white star marks the location of the star, whose stray light has been masked by the coronagraph.

Another surprise, the star of HIP 65426b is particularly young (14 million years), which does not match a priori with the absence of a disc of gas around the latter (according to current models), disc in which should be one or more gas giants much more massive than HIP 65426 b! In other words and still according to the current cosmogonic models, HIP 65426 b should not even exist (!), which proves in passing all the scientific interest of the JWST, which will undoubtedly require refining the explanatory models or even allowing completely reshuffle the cards of our hard-earned knowledge.

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