In more research presented at the AAS, Elena Manjavacas presents her team’s observations of tiny brown dwarfs using the Keck telescope. Instead of taking images, her team spread the light of the brown dwarfs out into a spectrum, or rainbow, and looked at the specific colors that correspond to light from different molecules. Brown dwarfs are objects big enough that they can burn heavy hydrogen in their cores but not big enough to burn regular hydrogen like a regular star. This means that they may ever so briefly act like stars before settling down to look (we think) more like gas giants. Manjavacas’ team wanted to see if light from brown dwarfs varied in systematic ways that would match with changing cloud patterns.

As a starting point, they looked at Beta Pictoris B, a brown dwarf just 115 light-years away, and twelve times larger than Jupiter. With a 3.5-hour rotation pattern, it is rotating faster than Jupiter and easy to observe during an Earth night. According to the release, the light reveals clouds of hot sand grains and other exotic elements. Potassium iodide traces the object’s upper atmosphere, which also includes magnesium silicate clouds. Moving down in the atmosphere is a layer of sodium iodide and magnesium silicate clouds. The final layer consists of aluminum oxide clouds. The atmosphere’s total depth is 446 miles (718 kilometers).

This paints a picture of a world we can’t actually see: a world with clouds, likely banding, and complex chemistry. As with so much of what we’re discussing today, these are just preliminary results, and we can’t wait to see what is learned as they survey more brown dwarfs for longer periods of time.

More Information

Hubble press release