Evidence of water clouds found on brown dwarf

An analysis of data obtained from a brown dwarf has showed strong evidence of the existence of clouds of water or water ice -- the first such clouds detected outside of our solar system.

WISE 0855 is only 7.2 light-years from the Earth and is the coldest-known object outside of our solar system. The brown dwarf is just barely visible at infrared wavelengths with the largest ground-based telescopes.

The scientists used the Gemini-North telescope in Hawaii and the Gemini Near Infrared Spectrograph to observe the brown dwarf over 13 nights for a total of about 14 hours.

"We would expect an object that cold to have water clouds, and this is the best evidence that it does," said study lead author Andrew Skemer from University of California - Santa Cruz.

A brown dwarf is essentially a failed star, having formed the way stars do through the gravitational collapse of a cloud of gas and dust, but without gaining enough mass to spark the nuclear fusion reactions that make stars shine.

With about five times the mass of Jupiter, WISE 0855 resembles that gas giant planet in many respects. Its temperature is about minus 10 degrees Fahrenheit.

"Our spectrum shows that WISE 0855 is dominated by water vapour and clouds, with an overall appearance that is strikingly similar to Jupiter," he said in a paper published in Astrophysical Journal Letters.

--IANS

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