Cataloged as VHS 1256 b, the planet is about 40 light-years away and orbits not one, but two stars over a period of 10,000 years.
Thanks to the images obtained by the James Webb telescope, a group of scientists discovered a strange planet with sandy clouds and that orbits two suns. Cataloged as VHS 1256 b, the planet is about 40 light-years away and orbits not one, but two stars over a period of 10,000 years. “VHS 1256 b is about four times farther from its stars than Pluto is from our Sun, making it a great target for Webb,” says Brittany Miles, the University of Arizona science team leader.
“Within those clouds, Webb detected both larger and smaller silicate dust grains, displayed in a spectrum,” adds Miles. “The finer silicate grains in your atmosphere can look more like tiny particles in smoke,” explains co-author Beth Biller, from the University of Edinburgh in the UK. “Larger grains could look more like very small, very hot sand particles,” he adds. VHS 1256 b has low gravity, compared to more massive brown dwarfs, which means that its silicate clouds can appear and stay higher in its atmosphere than the telescope could detect them.
Another reason why its skies are so turbulent is the age of the planet. In astronomical terms, it is quite young, as only 150 million years have passed since it formed. “We have identified silicates, but a better understanding of what grain sizes and shapes match specific cloud types will require a lot of additional work,” says Miles.
“This is not the last word on this planet, it is the beginning of a large-scale modeling effort to accommodate Webb’s complex data,” he remarks.
While all of the features the team observed have been detected on other Milky Way planets by other telescopes, other research teams typically identified only one at a time. “No other telescope has identified so many features at once for a single target,” explains co-author Andrew Skemer of the University of California, Santa Cruz.
“We are seeing many molecules in a single Webb spectrum detailing the planet’s dynamic cloud and weather systems,” he adds.
There will be much more to learn about VHS 1256 b in the coming months and years as science teams continue to analyze Webb’s high-resolution infrared data.
“There is a lot of performance in a very modest amount of telescope time. With just a few hours of observations, we have what seems like endless potential for additional discoveries,” Biller says.
The team’s paper, titled “JWST’s Early Publication Science Program for Direct Observations of Exoplanetary Systems II: A 1- to 20-micron spectrum of the planetary-mass companion VHS 1256-1257 b,” was published in The Astrophysical Journal Letters.
source : https://arxiv.org/abs/2209.00620