The news of discoveries made thanks to the continues James Webb Space Telescope. Most recently there was talk of the discovery of another supernova in the galaxy MRG-M0138 or images of Uranus (a planet that could be visited by a Chinese probe in the coming years). One of the latest news concerns the Brown dwarfs, celestial body halfway between a real star and a gas giant. In December 2023 they had already written about how JWST has been engaged in their discovery, but now there are further discoveries in this regard.
In particular, we focused on this 12 cool brown dwarves Two of them (W1935 and W2220) are very similar in behavior and properties of temperature, brightness and composition. The scientists then continued to focus on it W1935 which showed a spectral emission related to the methane. Why does a brown dwarf show an emission associated with this molecule?
The James Webb Space Telescope, methane and auroras in brown dwarfs
The researchers suspected that it was one phenomenon attached to Northern lights (This phenomenon is possible in varying degrees on Earth, but also on other planets such as Mars, Jupiter and Saturn). The Northern lights They can arise from the interaction of the magnetic field, atmosphere and solar emission. W1935 However, there is no companion star that could produce the phenomenon in its atmosphere.
The hypothesis is that the Northern lights of this Brown dwarf arise through the interaction of interstellar plasma or an active natural satellite nearby (in the solar system there are examples with Io for Jupiter and Enceladus for Saturn). Thanks to James Webb Space Telescope (and to the instrument NIRSpec) methane-related infrared emissions could be detected in the upper atmosphere W1935 which gets warmer with increasing altitude and not the other way around.
Ben Burningham (from the University of Hertfordshire and co-author of the study) said “This temperature inversion is really worrying. We have seen this type of phenomenon in planets with a nearby star that can heat the stratosphere, but to see it in an object with no obvious external heat source is absurd.”.
W1935 It is the first celestial object with auroras produced by methane emission outside the solar system (although more data is needed to confirm this discovery). Its temperature is around 200 °C, much hotter than Jupiter. If the findings of the James Webb Space Telescope There will be a new piece to understanding these elusive objects.