James Webb’s ‘historic’ images show exoplanet in unprecedented detail | James Webb Space Telescope

A blazing gas giant shrouded in dusty red clouds has been revealed in unprecedented observations of a planet beyond our solar system.

The sightings, which astronomers say marked a “historic moment for astronomy,” are the first direct images of a planet beyond our solar system by NASA’s $10 billion (8.65 billion pounds). James Webb Space Telescope. They are also the first images of an exoplanet using infrared light, which gives a much more accurate indication of a planet’s mass and temperature and will allow astronomers to detect the movement of clouds drifting across the sky from the planet.

“This is truly a historic moment for astronomy,” said Professor Sasha Hinkley, an astronomer based at the University of Exeter who co-led the observations. “James Webb is going to open the door to a whole new class of planets that were completely inaccessible to us and by observing them in a wide range of wavelengths we can study their compositions much more thoroughly.

“We will be able to detect the presence of time.”

Imaging exoplanets directly is a huge technical challenge because the host star is much brighter. The focus of the latest observations, HIP 65426 b, is a gas giant about 5 to 10 times the mass of Jupiter located at 385 Light years of the earth in the Centaur constellation.

It is about 100 times farther from its host star than Earth is from the sun, making it easier to distinguish. But is still more than 10,000 times fainter than its host star – the equivalent of trying to spot a firefly next to a large lighthouse over 50 miles away.

The latest observations put the planet’s atmospheric temperature at around 1,300°C (2,370°F) and suggest that its atmosphere contains clouds of red-hued silicate dust. “It would be a terrible place to live,” Hinkley said. “You would be roasted alive if you could float in the atmosphere.”

Previously, astronomers had obtained direct images of around 20 exoplanets, including HIP 65426 b, using ground-based telescopes. But that meant coping with the noise introduced by Earth’s atmosphere and limiting observations to a narrow range of visible wavelengths. By contrast, the latest images, captured in the cold, airless environment of space, cover a wide range of wavelengths, including infrared, which accounts for most of the light produced in the atmosphere. of the planet.

“The best wavelength to observe a planet is the one at which it produces the most intrinsic light, because this is directly related to the temperature of the planet,” said Dr. Beth Biller, co-principal investigator and astronomer at the University of Edinburgh. .

HIP 65426 b is only 10 to 20 million years old, much younger than the 4.5 billion year old Earth, and the latest observations give new insight into how Jupiter and Saturn looked at their beginnings.

Dr Vivien Parmentier, associate professor of physics at Oxford University, who was not involved in the latest work, said: “Opening a new window into the universe always brings surprises. Planets get bigger and smaller over time and this little planet seems to have shrunk faster than we expected. It gives us incredible insight into the formation of planets and the formation of our own solar system.

In the future, the James Webb is expected to make detailed observations of more distant Earth-like planets, including those with potentially habitable conditions.

The results are published in a prepublication displayed on the Arxiv website.

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