Methane Emissions Hint at Hidden Exomoon Around Brown Dwarf

Using the James Webb Space Telescope (JWST), scientists stumbled upon a remarkable find: methane emissions from a brown dwarf, often referred to as a "failed star." This unexpected discovery hints at the presence of aurorae on the brown dwarf's surface and raises the intriguing possibility of an unseen exomoon in orbit around it.

Brown dwarfs, being cold and solitary celestial bodies, aren't typically associated with emitting infrared light from methane. Yet, the JWST's investigation of 12 brown dwarfs led to this surprising revelation. These failed stars, it seems, can produce aurorae akin to those witnessed on Earth, Jupiter, and Saturn. The absence of a nearby star suggests that any aurorae observed on this particular brown dwarf may be generated by a concealed active moon.

The object of focus in this study is the brown dwarf CWISEP J193518.59–154620.3 (W1935), located 47 light-years away. Despite its mass being uncertain, ranging from 6 to 35 times that of Jupiter, W1935 boasts a surface temperature akin to that required for baking chocolate chip cookies.

The presence of methane emissions around W1935 marks a departure from previous observations of failed stars. Further analysis revealed a temperature inversion in its atmosphere, a phenomenon typically associated with planets orbiting stars that heat their atmospheres from above. This raises questions about the source of additional heat in W1935's upper atmosphere.

Drawing comparisons with gas giants in our solar system, such as Jupiter and Saturn, the researchers speculate that aurorae may be driving the methane emissions and temperature inversion observed around W1935. However, the absence of stellar winds from a nearby star suggests an alternative explanation involving an active moon orbiting the brown dwarf.

While more evidence is needed to confirm the existence of a moon orbiting a brown dwarf, these initial findings underscore the profound impact of the JWST in uncovering hidden phenomena within the universe. Each observation with this remarkable telescope presents the possibility of unlocking new and unexpected discoveries, propelling scientific understanding forward.