A weird alien world cloaked in clouds of sand-like silicate granules has been discovered by the James Webb Space Telescope.
The exoplanet finding, revealed in a recent paper as the first of its kind, was made by the NIRSpec and MIRI instruments on the James Webb Space Telescope. Astronomers discovered indications of silicate-rich clouds surrounding a brown dwarf roughly 20 times the size of Jupiter in the data. The discovery backs up several previous speculations concerning these strange planet-like planets.
Brown dwarfs are weird objects that are not quite large enough to ignite into stars but are also not small enough to be considered planets. Brown dwarfs, while unable to consume normal hydrogen, can generate their own light and heat by burning deuterium (a less common isotope of hydrogen that contains an extra neutron).
VHS 1256 b is a brown dwarf that orbits two tiny red dwarf stars 72 light-years from Earth in the constellation Corvus, or the Crow, in the southern sky. Astronomers spotted the odd exoplanet in 2016, and its reddish glow has perplexed them ever since. They suspected that the glow was created by some kind of atmosphere. According to Forbes, observations from the James Webb Space Telescope have now corroborated those predictions, demonstrating that VHS 1256 b must be surrounded in dense clouds filled of sand-like silicate grains.
Water, methane, carbon monoxide, carbon dioxide, sodium, and potassium were also found in the atmosphere of VHS 1256 b by Webb.
"We will know more from iterations on the data reduction," said Brittany Miles, an astronomer at the University of California, Irvine and the project's principal researcher, in an email to Space.com. "So far, it appears to be pretty close to theoretical expectations."
The Webb data were so thorough that they revealed that the ratio of the various gases changes throughout the atmosphere of VHS 1256 b, implying that the atmosphere is not static, but rather chaotic and turbulent.
"There is an expected ratio of, example, methane and carbon monoxide in a tranquil atmosphere," Sasha Hinkley, an astronomer at the University of Exeter in the United Kingdom and one of the study's co-authors, told Forbes (opens in new tab). "However, we're finding that this ratio is significantly skewed in many planetary atmospheres, implying that there is turbulent vertical mixing in these atmospheres, dredging up carbon dioxide from deep down to mix with methane higher up in the atmosphere."
VHS 1256 b is small for a brown dwarf, suggesting that the body is young. The exoplanet orbits its two parent stars 360 sun-Earth distances apart in an oval-shaped orbit that takes 17,000 years to complete.
Reference(s): arXiv