Distant planet’s features revealed by Webb Telescope
Researchers observing with NASA’s James Webb Space Telescope have identified features in the atmosphere of planet VHS 1256 b.
Researchers observing with NASA’s James Webb Space Telescope have pinpointed silicate cloud features in the atmosphere of distant planet VHS 1256 b. They have also identified that the planet’s atmosphere is constantly rising, mixing, and moving during its 22-hour day, bringing hotter material up and pushing colder material down. The resulting brightness changes are so dramatic that it is the most variable planetary-mass object known to date. Researchers also made extraordinarily clear detections of water, methane and carbon monoxide with Webb’s data, and found evidence of carbon dioxide. This is the largest number of molecules ever identified all at once on a planet outside our solar system.
Prof Beth Biller from the School’s Institute for Astronomy was part of the research team, which was led by Brittany Miles of the University of Arizona.
Planet VHS 1256 b is about 40 light-years away and orbits not one, but two stars over a 10,000-year period. It is about four times farther from its stars than Pluto is from our Sun, which means the planet’s light is not mixed with light from its stars.
VHS 1256 b has low gravity compared to more massive brown dwarfs, which means that its silicate clouds can appear and remain higher in its atmosphere where Webb can detect them. Part of the reason why its skies are so turbulent is the planet’s age: in astronomical terms, it’s quite young - only 150 million years have passed since it formed - and it will continue to change and cool over billions of years.
The research team considers these findings to be the first “coins” in a treasure chest of data. They’ve only begun identifying its contents however, and better understanding of which silicate grain sizes and shapes match specific types of clouds is going to take a lot of additional work.
The team came to these conclusions by analyzing spectra gathered by two instruments aboard Webb: the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI). Although all of the features the team observed have been spotted on other planets elsewhere in the Milky Way by other telescopes, other research teams typically identified only one at a time. There will be plenty more to learn about VHS 1256 b in the months and years to come as this team – and others – continue to sift through Webb’s high-resolution infrared data.
Beth Biller commented:
There’s a huge return on a very modest amount of telescope time. With only a few hours of observations, we have what feels like unending potential for additional discoveries.
The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.