What’s the weather like out there? No, I don’t mean in your city, or your state or even your country… or planet — I’m talking about really out there: 35.2 trillion miles, in fact, and not on a planet at all but rather on a brown dwarf. (That’s a so-called “failed star,” if you’re the type who likes to point out negatives.)
It might seem a purely hypothetical question but astronomers have actually managed to directly observe “weather” on a brown dwarf, using the incredible imaging power of the European Southern Observatory’s Very Large Telescope (VLT) located on the Cerro Paranal mountain in Chile’s Atacama desert.
Changing patterns of dark and light regions have been observed moving around the brown dwarf as it rotates — similar to what might be seen on a gas giant planet like Jupiter or Saturn.
“Previous observations suggested that brown dwarfs might have mottled surfaces, but now we can actually map them,” said Ian Crossfield from the Max Planck Institute for Astronomy, the lead author of these findings. “Soon, we will be able to watch cloud patterns form, evolve, and dissipate on this brown dwarf — eventually, exometeorologists may be able to predict whether a visitor to Luhman 16B could expect clear or cloudy skies.”
The dwarf, named WISE J104915.57-531906.1B (and informally known as Luhman 16B) is one in a binary pair located 6 light-years away. These are the closest known brown dwarfs to our solar system and the third closest star system overall.
Since brown dwarfs are a kind of missing link between the coolest stars and the most massive “hot Jupiters,” learning how to accurately observe their changing weather will help astronomers be able to do the same on actual exoplanets.
It’s kind of like training wheels for future exometeorologists.
The team’s paper “A Global Cloud Map of the Nearest Known Brown Dwarf” will be published in the January 30 issue of the journal Nature.
Source: ESO news release