Our solar system has already discovered 6,000 outer planets, also known as exoplanets. However, one moon, Eksokuu, has yet to be found. These moons orbit planets or other celestial bodies outside our solar system and are typically much smaller than the planets themselves. While moons are common in our solar system, the James Webb Space Telescope indirectly discovered an exomoon orbiting a brown dwarf, which is a dark “failed star” larger than Jupiter.
The dwarf, known as W1935, was previously studied by Webb, which found surprising infrared methane emissions from the body. This heat radiation produces aurora borealis on the dark celestial body, indicating that an energy source is nearby, possibly a moon or multiple exomoons. Brown dwarfs like W1935 do not produce enough heat on their own for methane to emit infrared light, suggesting the presence of a moon.
Located 47 light years from Earth, W1935 is larger than Jupiter with a surface temperature over 200 degrees Celsius. The methane emissions and temperature inversion in W1935’s atmosphere are similar to those seen on gas giants like Jupiter and Saturn in our solar system. These phenomena are caused by interactions with nearby moons that release material, such as lava and water vapor, into space, generating colorful light radiation near the poles of the planets.
Researchers are still gathering evidence to confirm the existence of the exomoon orbiting the brown dwarf W1935. The discovery was introduced in the science journal Nature, marking a significant milestone in exoplanet research. Further observations and study are needed to provide more insights into these distant celestial bodies and their unique characteristics.