The James Webb Space Telescope discovers its first exoplanet close to Earth

Launched on December 25, 2021, the James Webb Telescope continues to revolutionize astronomical observation. And that's not all, because it has enabled scientists to make astonishing discoveries, such as this exoplanet close to Earth that appears to be in a precarious phase of its existence.. 

Since it became operational, 1.5 million kilometers from Earth, this telescope has managed to capture numerous exoplanets. On this subject, astrophysicist Anne-Marie Lagrange states the following in the journal Nature: “It has spent a great deal of time observing planets that have never been imaged before.” 

Nevertheless, while this may not seem spectacular, it is important to understand that observing such stars is no easy task. They are very dim because they do not have significant heat at their center. And that's not all, because they orbit a star that blinds astronomers when they try to find them. 

However, the James Webb Telescope has a formidable advantage: its coronagraph, an instrument directly inspired by the phenomenon caused by a solar eclipse, which masks the light emitted by the star in order to find the stars that orbit around it. In addition, its MIRI spectrograph is capable of imaging stars that are barely visible in the sky using infrared.

So, scientists decided to point this device at TWA 7, a star located in our galaxy “only” a hundred light-years away from us. The reason this star intrigues researchers is its age. It is 6.4 million years old and has allowed planetary disks to form in its belt. But that's not all, because observations using the Sphere instrument on the Very Large Telescope (VLT) in Chile revealed three large rings around it. 

It was in the second ring that the James Webb Space Telescope found a light source named TWA 7b. Astronomers have identified this star as a cold planet with a mass comparable to that of Saturn. However, it seems impossible that life could have appeared on this planet, as it is gaseous. In other words, it is entirely composed of different gases. 

But this planetary system is promising, and new observations, such as those made with the Extremely Large Telescope (ELT) in 2028, could lead to further discoveries. And why not find traces of life on another rocky planet besides Earth?