In our universe, collisions are not that rare. However, this is the first time astronomers have observed a head-on collision between two giant exoplanets.
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[EN VIDÉO] Exoplanets What are exoplanets, where do they occur and why are they so interesting? Video answer…
It was an astronomy enthusiast who first noticed it. Something strange in a star’s light curve. A luminosity that has doubled in the infrared range for three years. Then a star that gradually disappeared from the eyes of the observers. Completely unusual phenomenon.
An unusual phenomenon caused by exoplanets
So much so that an international team of astronomers was formed to study this star called ASASSN-21qj. Over several months, they carried out numerous observations and simulations, which they report on today in the journal Nature. And all the data seems to agree with a single idea: the phenomenon was caused by a collision between two ice giant exoplanets.
This is the first time such an event has been observed by astronomers. Models show that such a collision between exoplanets may have produced the infrared light originally detected by NASA’s Neowise mission. As the resulting debris cloud gradually moved in front of the star, its visible brightness decreased.
A collision of exoplanets is to be investigated
Then the puzzle is solved. But astronomers aren’t quite done with ASASSN-21qj yet. In the coming years, they hope to observe the scattering of starlight by the dust left over from this collision. Use of ground-based telescopes. But perhaps most of all thanks to the James Webb Space Telescope. They are already considering that the new planet formed during the collision could be surrounded by a procession of lunar moons made up of the remnants of the shock.