In addition to providing a wealth of information on the start of the universe, the James Webb space telescope since its launch in 2021 has obtained precious data on various planets already known beyond our solar system, called exoplanets. Now, for the first time, Webb has discovered an exoplanet that does not know before.
Webb has directly imagined a young giant gas planet about the size of Saturn, the second planet of our solar system, in orbit around a smaller star than the sun located about 110 light years from Earth in the constellation of Antlia, researchers said. A light year is the distance that the light moves in one year, 5.9 billions of miles [9.5 trillion km].
Most of the 5,900 exoplanets discovered since the 1990s have been detected using indirect methods, as by observing the light gradation of the light of a star when a planet passes before it, called transit method. Less than 2% of them were directly imagined, as webb did with the newly identified planet.
Although this planet is large when it is considered in the context of our solar system, it is in fact the least massive ever discovered by direct imaging – 10 times less massive than the previous door. This testifies to the sensitivity of webb instruments.
This discovery was made using a coronagrapher produced in French, a device that blocks the bright light of a star, installed on the average infrared instrument of webb, or Miri.
“Webb opens a new window-in terms of mass and distance from a star planet-exoplanets who have not been accessible to observations so far. It is important to explore the diversity of exoplanetary systems and understand how they are formed and evolved,” said astronomer Anne-Marie Lagrange of the French research agency CNRS and Lira the study.
The planet orbits its host star, called TWA 7, at a distance approximately 52 times higher than the orbital distance from the Earth of the Sun. To put this in perspective, the planet most outside of our solar system is about 30 times further from the sun than the earth. The transit method to discover exoplanets is particularly useful for locating orbits near their host star rather than much further like that newly identified.
“Indirect methods provide incredible information for planets close to their stars. Imaging is necessary to detect and characterize the planets further, generally 10 times the distance to the earth to a worthy,” said Lagrange.
The birth of a planetary system begins with a large cloud of gas and dust – called molecular cloud – which collapses under its own gravity to form a central star. The remains of material revolving around the star in what is called a protoplanetary disc forms planets.
The star and the planet of this research are practically newborns – aged about 6 million years, compared to the age of the sun and our solar system over 4.5 billion years.
Due to the angle to which this planetary system is observed – the examining essentially from above rather than side – the researchers were able to discern the structure of the remaining disc. It has two large concentric ring structures composed of rocky and dusty materials and a narrow ring in which the planet is seated.
Researchers do not yet know the composition of the atmosphere of the planet, although future webb observations can provide an answer. They are not certain either as the planet, being as young as it is, always gains mass by accumulating additional materials that surround it.
Although this planet is the smallest ever imaged directly, it is still much more massive than rocky planets like the earth which could be good candidates for the search for life beyond our solar system. Even with its huge abilities to observe the cosmos in almost infrared and infrared wavelengths, webb is still unable to imagine the exoplanets of the earth directly.
“In the meantime, I hope that direct imaging projects of land -shaped planets and the research of possible signs of life will become a reality,” said Lagrange.
