Astronomers Investigate The Layered Atmosphere Of A Brown Dwarf

In our solar system, Jupiter is the biggest planet of them all. It's a massive gas giant, many times larger than Earth. Despite how large Jupiter is and its stature as the biggest planet in our solar system, it's very small compared to some gas giants orbiting other stars. These types of supermassive planets are known as super-Jupiters and can weigh up to 13 times Jupiter's mass.

Astronomers have analyzed the composition of some super-Jupiter planets and studied their atmospheres in general, but such investigation is difficult because details of the atmosphere of these planets get lost in the glare of the stars the planets orbit. Researchers are trying to eliminate that problem by researching planets orbiting brown dwarfs.

Brown dwarfs are failed stars 80 times Jupiter's mass. They form out of a collapsed cloud of gas, just as stars do, but lack enough mass to become hot enough to sustain nuclear fusion in their core. Brown dwarfs are related to super-Jupiter planets, with both objects having similar temperatures and being extremely massive. However, brown dwarfs also have complicated and varied atmospheres.

The only real difference between a brown dwarf and a super-Jupiter is how they form. Super-Jupiters form around stars, and brown dwarfs typically form in isolation. Astronomers studied the layer-cake cloud structure in a nearby free-floating brown dwarf known as 2MASS J220811363+2921215 using the Keck Observatory in Hawaii. Scientists are studying the near-infrared light, the colors, and brightness variations of the layer-cake cloud structure of the brown dwarf.

The team is using an instrument called the Multi-Object Spectrographic for Infrared Expiration to analyze fingerprints of various chemical elements in the clouds and how they changed over time. This study marks the first time the instrument has been used for work of this type. The data gathered gives astronomers a holistic view of atmospheric clouds around the brown dwarf, providing more detail than previous observations. This particular brown dwarf is being studied because it's very young and extremely bright, radiating heat strongly in near-infrared.

Data revealed the spectrum of clouds containing hot sand grains and other exotic elements, including potassium iodide traces in the upper atmosphere, which also includes magnesium silicate clouds. The atmosphere's next layer is sodium iodide with magnesium silicate clouds. The final layer is aluminum oxide clouds. The total depth of the atmosphere of the brown dwarf is 446 miles.