Thanks to the coronographer who masks the light of the star, we see that of the Exoplanet TWA7B appear. © ESA/Webb, NASA, CSA, AM LAGRANGE, M. Zamani (ESA/Webb)
It is a great first for the most powerful space telescope in the world. Indeed, a team has just announced its very first detection of exoplanet. It is excessively young, because the estimated age of debris around its parent star is the lowest known for such a disc, about 6.4 million years. Our ancestor Toumaï barely fought the earth in his capacity as a biped at the time of the formation of this disc, that is to say if it is recent on the galactic scale.
This star was baptized this antilae and is 111 light years from us-the door next to our Milky Way-in the direction of the Constellation of Andromeda. It is also twice as massive as the sun.
Astronomers have been scrutinizing it for a long time, because her very young age makes her exciting and instructive. In particular, it is his debris disc, or protoplanetary disk, which is studied, precisely where the planets are formed.
The star this antilae is in polar sight, which is ideal
By masking the light of the star (center), we clearly see an empty area appear in the debris disc. This is where the exoplanet CC#1 organs. © A-M Lagrange et al (Nature, 2025)
This antilae, also called TWA7, is perfectly oriented for this type of observation, because it is in polar sight. As we can see by above, the famous debris disc is perfectly arranged to be characterized with three very distinct rings (R1, R2 and R3). The technique used is that of the coronograph, which masks the light of the star to reveal by contrast that of possible companions.
Around TW7, an infrared source is actually a baby planet
In medium infrared, there are three distinct light sources: a background galaxy (BGD Galaxy), a background star (BGD Star) and CC#1, the discovery exoplanet. © A-M Lagrange et al (Nature, 2025)
The exoplanets detected in direct optics, and not by transit or radial speed, the other main methods of detection, are quite rare, around 1 or 2 % of the 6000 exoplanets identified to date.
Thanks to the precision of the Miri instrument (average infrared), astronomers have identified a light source in the R2 ring around this antilae (noted CC#1 on the photo). In the absence of data showing a movement of this source around the parent star, they had to eliminate hypotheses on the possible origin of this source: substantive galaxy or object of the solar system in preview.
Tw7B, the name given to this exoplanet, has a rare characteristic. It only makes one third of the mass of Jupiter, or 100 times that of the earth. However, never an extraness planet of such a low mass had been pictorial.
Most likely is therefore a planet located about 50 times the Earth-Sun distance, which would make it a very cold planet and suddenly almost a gaseous world.
One can easily imagine that the JWST will discover other exoplanets thanks to its extraordinary sensitivity. Stay tuned…
Want to save even more? Discover our selected promo codes for you.
