Water-ice clouds exist on the familiar gas giant planets in our own solar system – Jupiter, Saturn, Uranus, and Neptune – but have never been seen beyond our solar system, until now. The Astrophysical Journal Letters published the new findings of water-ice clouds beyond our solar system yesterday (September 9, 2014).
The findings come from observations made the Las Campanas Observatory in Chile by Jacqueline Faherty and a team from Carnegie Institution for Science. These astronomers used a near-infrared camera to detect an object called WISE J085510.83-071442.5, or W0855. This object was first seen by NASA’s Wide-Field Infrared Explorer satellite; it wasn’t known if ground-based observatories would be able to spot it.
The team acquired 151 images of W0855, taken over three nights. Then they combined the images.
A comparison of the team’s near-infrared images of W0855 with models for predicting the atmospheric content of brown dwarfs showed evidence of frozen clouds of sulfide and water.
Brown dwarfs are sometimes described as hybrids, between planets and stars in mass. They are somewhat similar to the gas giant planets in our solar system, which also have water-ice clouds. W0855, in particular, is the fourth-closest known system to our own sun, practically a next-door neighbor in astronomical terms at only about 7 light-years away. W0855 is also the coldest brown dwarf yet known, with a temperature between 225 to 260 K (-55 to 8 °F).
Bottom line: Astronomers have found the first evidence for water-ice clouds on an object beyond our solar system. It’s a brown dwarf, called WISE J085510.83-071442.5, or W0855. This object is one of our closest neighbors, only 7 light-years away.
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.