In addition to providing a treasure of information about the early universe, the James Webb space telescope since its launch of 2021 has obtained valuable data on several planets already known beyond our solar system, called Exoplanets. Now, for the first time, Webb has discovered an Exoplanet not previously known.
Webb has directly photographed a giant planet of young gas in the size of Saturn, the second largest planet in our solar system, orbiting a star smaller than the sun located about 110 light years of the earth in the constellation of Antlia, the researchers said. A light year is the distance of light in a year, 5.9 billion miles [9.5 trillion km].
Most of the approximately 5,900 exoplanets discovered since the 1990s have been detected using indirect methods, as through the observation of the light attenuation of the light of a star when a planet passes in front of it, called a transit method. Less than 2% of them have been taken directly, as Webb did with the newly identified planet.
While this planet is large when considered in the context of our solar system, it is actually the least massive that is discovered through direct images, 10 times less massive than the previous registration holder. This speaks of the sensitivity of Webb instruments.
This discovery was achieved using a coronagraph produced by French, a device that blocks the bright light of a star, installed in the webb or Miri’s middle infrared instrument.
“Webb opens a new window, in terms of mass and the distance of a planet to the star, of exoplanets that had not been accessible for the observations so far. This is important to explore the diversity of the exoplanetary systems and understand how they form and evolve,” said the progress of the research agency of the French research agency of the French research agency.
The planet orbits its host star, called TWA 7, at a distance approximately 52 times greater than the orbital distance of the Earth of the Sun. To put that in perspective, the outermost planet of our solar system, Neptune, orbit about 30 times further from the sun than the earth. The transit method to discover exoplanets is particularly useful to detect those that orbit near their host star instead of much further as the newly identified.
“Indirect methods provide incredible information for planets close to their stars. Images are needed to detect and characterize the planets further, generally 10 times the distance of the Earth-Sun,” 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 excess material revolving around the star in what is called a protoplanetary disk forms planets.
The star and the planet in this investigation are practically newborns, approximately 6 million years, compared to the age of the sun and our solar system of approximately 4.5 billion years.
Due to the angle in which this planetary system is observed, essentially looking from above instead of from one side, the researchers could discern the structure of the remaining disc. It has two wide concentric ring structures formed by rocky and dusty material and a narrow ring in which the planet is sitting.
Researchers still do not know the composition of the planet’s atmosphere, although webb’s future observations can provide an answer. Nor are they sure if the planet, being as young as it is, is still gaining mass accumulating additional material that surrounds it.
While this planet is the smallest ever directly photographed, it is still much more massive than rocky planets such as Earth that could be good candidates in the search for life beyond our solar system. Even with its tremendous capabilities to observe the cosmos in nearby infrared wavelengths and middle infrared, Webb cannot directly imagine the exoplanets of terrestrial size.
“Looking to the future, I hope that direct planet image projects similar to the land and searches for possible signs of life come true,” said Lagrange.
