A team from the University of Hawaii announces that they have isolated a planet formed only a few million years ago. Relying on the powerful Subaru telescope, the astronomers were able to directly photograph the object in formation. Details of the study are published in the Monthly Notices of the Royal Astronomical Society .
Two main methods allow the detection of extra-solar planets. On the one hand, that of the transit, aims to detect slight dips in stellar luminosity, testifying to the passage of an exoplanet in front of its star from our point of view.
The second, that of radial velocity, is to assess changes in the wavelength of light from a star. In the idea, a planet orbiting around a star will exert a slight gravitational influence that will cause it to wobble slightly. The wavelength of its light will then shift as it moves closer and further away from us. From our point of view, this "wobble" will therefore testify to the presence of a planet.
That being said, if these two methods have enabled the discovery of several thousand planets outside our system, they are on the other hand indirect. In other words, astronomers do not spot these planets "directly" around their star. Their presence is simply deduced for the simple and good reason that these worlds are too close to their star. They are therefore drowned in their light.
However, sometimes planets are far enough from their star to be directly visible. This is the case of this new object, named 2M0437b .
Located in a stellar "nursery" (Taurus Cloud) just over 400 light years away from Earth, this exoplanet evolves at about 10.5 billion kilometers of its star, or about a hundred times the Earth-Sun distance. Although far removed from its host, sophisticated "adaptive" optics were still required to compensate for the image distortion caused by the Earth's atmosphere.
2M0437b also has the benefit of being still very young, formed a few million years ago only. In this sense, it will advance our understanding of how the planets evolve over time, helping to shed new light on the origin of the solar system and the Earth. Researchers estimate that this planet is a few times more massive than Jupiter , displaying a surface temperature roughly equivalent to that of erupting lava from Kīlauea Volcano.
In the future, observations with space observatories such as Hubble and the soon-to-be-launched James Webb Telescope could identify the different gases present in its atmosphere, and we reveal why not a lunar disk.
