Researchers using NASA’s James Webb Space Telescope have identified silicate cloud structures in the atmosphere of a faraway planet. Throughout its 22-hour day, the atmosphere is continually rising, mixing, and flowing, sending hotter stuff above and cooler material downward.
Evidence of water, methane, and carbon monoxide, as well as indications of carbon dioxide
The ensuing brightness variations are so severe that it is the most changeable object of planet-like mass yet discovered. Using Webb’s data, the team led by Brittany Miles of the University of Arizona identified evidence of water, methane, and carbon monoxide, as well as indications of carbon dioxide. This is the most number of molecules ever discovered simultaneously on an extrasolar planet.
The planet, designated VHS 1256 b, is around 40 light-years distant and circles not one, but two stars over a period of 10,000 years. “VHS 1256 b is almost four times farther away from its stars than Pluto is from our Sun, making it an ideal target for Webb,” Miles explained.
Temperatures reach a blistering 1,500 degrees Fahrenheit in its upper atmosphere,
This indicates that the planet’s light is not mingled with starlight. Temperatures reach a blistering 1,500 degrees Fahrenheit in its upper atmosphere, where the silicate clouds are roiling (830 degrees Celsius).
Webb identified both bigger and smaller silicate dust grains within these clouds, as seen by a spectrum. Co-author Beth Biller of the University of Edinburgh in Scotland remarked that the finer silicate grains in the planet’s atmosphere may resemble smoke particles. The bigger grains may resemble tiny, very heated sand particles.
The low gravity of VHS 1256 b compared to more massive brown dwarfs allows silicate clouds to form and persist higher in its atmosphere, where Webb can detect them. The planet’s age also contributes to its tumultuous sky. In terms of astronomy, it is fairly young. Since its formation, just 150 million years have elapsed, and it will continue to evolve and cool over billions of years.
These results are, in many respects, the first “coins” extracted from a spectrum that researchers perceive as a treasure box of data. In many respects, they have only just begun to recognize its contents.
“We’ve found silicates, but knowing which grain sizes and shapes correspond to particular cloud types will need a substantial amount of more effort,” Miles said. This is only the beginning of a massive modeling effort to accommodate Webb’s complicated data.
Other telescopes have detected all of the traits the team found on other planets in the Milky Way, but other study teams normally identify only one at a time.
No other telescope has simultaneously found so many characteristics on a single target
“No other telescope has simultaneously found so many characteristics on a single target,” University of California, Santa Cruz co-author Andrew Skemer stated. “A single spectrum from Webb reveals an abundance of chemicals that depict the planet’s dynamic cloud and weather systems.”
The researchers reached these results by examining spectra collected by the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument aboard the Webb spacecraft (MIRI). As the planet orbits so far from its stars, the researchers were able to examine it directly rather than utilizing the transit method or a coronagraph.
In the coming months and years, this team – and others – will continue to sift through Webb’s high-resolution infrared data to learn more about VHS 1256 b. Biller added, “There is a tremendous return on a very modest amount of telescope time.” After only a few hours of monitoring, the potential for more discoveries appears to be limitless.
What may this planet evolve into billions of years from now? Due to its great distance from its stars, it will gradually become colder, and its skies may clear up.
The researchers observed VHS 1256 b as part of Webb’s Early Release Science program, which aims to transform the astronomical community’s ability to characterize planets and their formation disks.
The research titled “The JWST Early Release Science Program for Direct Studies of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b” will be published on March 22 in The Astrophysical Journal Letters.
The James Webb Space Telescope is the world’s finest observatory for space science. Webb will unravel puzzles in our solar system, see distant worlds surrounding other stars, and investigate the universe’s intriguing origins, architecture, and our role within it. Webb is a NASA-led multinational effort involving ESA (European Space Agency) and the Canadian Space Agency as partners.