James Webb’s “historic” photos show exoplanets in unprecedented detail | James Webb Space Telescope

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

The observations, which astronomers said represented a “historic moment for astronomy”, are the first direct images of a planet outside our solar system by NASA worth $10 billion (£8.65 billion) James Webb Space Telescope. It’s also the first images of an exoplanet to use infrared light, which gives a more accurate indication of the planet’s mass and temperature and allows astronomers to detect the motion of drifting clouds across the planet’s sky.

“This is really a historic moment for astronomy,” said Professor Sasha Hinckley, an astronomer at the University of Exeter, who co-led the observations. “James Webb will open the door to a whole new class of planets that have been completely out of our reach and by observing them over a wide range of wavelengths we can study their structures in a more in-depth way.

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

Direct imaging of exoplanets is a major technical challenge because the host star is much brighter. The latest observations, HIP 65426 b, focus on the presence of a gas giant about five to 10 times the mass of Jupiter found in 385 light years from 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 it is still more than 10,000 times lighter than its host star – the equivalent of trying to spot a firefly next to a large lighthouse from more than 50 miles away.

The most recent observations indicate that the planet’s atmosphere is about 1,300 degrees Celsius (2370 degrees Fahrenheit) and indicate that its atmosphere contains red clouds of silicate dust. “It would be a terrible place to live,” Hinckley said. “You’d be roasted alive if you could float.”

Previously, astronomers had obtained direct images of 20 or so exoplanets, including HIP 65426 b, using ground-based telescopes. But this means counteracting noise from Earth’s atmosphere and limiting observations to a narrow range of visible wavelengths. By contrast, the latest images, taken from the cold, airless environment of space, cover a wide range of wavelengths, including infrared, which accounts for most of the light produced in the planet’s atmosphere.

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

HIP 65426 b is only 10 to 20 million years old, much younger than Earth’s 4.5 billion years old, and the latest observations are giving new insights into how Jupiter and Saturn looked in their childhood.

Dr. Vivien Parmentier, Associate Professor of Physics at the University of Oxford, who was not involved in the latest work, said: “Opening a new window into the universe always brings surprises. Planets are forming large and shrinking over time and it seems that this small planet has shrunk faster than we expected. This gives us Amazing insights into how planets formed and how our solar system formed.”

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

The results have been published in a preliminary version published on Arxiv website.