Researchers used the SPHEREx telescope to get a close-up look at 37 brown dwarfs, often called failed stars. These cosmic loners have atmospheres rich in water, methane, and carbon dioxide. "No two brown dwarfs are alike," said Zafar Rustamkulov from Caltech. The team now hopes to study thousands more objects.
Brown dwarfs are often described as cosmic loners, drifting through the dark void of space without the light of a parent star.
Their atmospheres are chemically similar to those of our solar system's gas giant planets.
"They're kind of goth," said Zafar Rustamkulov from Caltech.
He added that unlike exoplanets, free-floating brown dwarfs are completely independent celestial objects that will fade into eternity alone.
SPHEREx, short for Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer, can detect light wavelengths that ground-based telescopes can't.
This is because Earth's atmosphere absorbs these wavelengths.
Rustamkulov said they are "picking up light from the deep, red clouds of brown dwarfs all over the sky."
The team studied 37 nearby brown dwarfs across a spectrum of light including 102 wavelengths.
The spectra of brown dwarfs observed by SPHEREx revealed that their atmospheres are rich in water, carbon dioxide, carbon monoxide, and methane.
"We're seeing the signatures of these molecules and how they change from object to object across the entire temperature regime," said J. Davy Kirkpatrick from Caltech.
The team has thousands more brown dwarfs to analyze and hopes to learn more about their diversity in the universe.
SPHEREx's wide wavelength coverage has made it especially useful for observing brown dwarfs.
Some of these failed stars are at an extreme stage of change, with their clouds clearing and atmospheres rich in methane.
However, state-of-the-art models are struggling to match the data when it comes to these cloudy transitions.
"No two brown dwarfs are alike," Rustamkulov said, emphasizing their unique nature even at the same temperature.