Water clouds have been spotted for the first time outside of our solar system. They were found on a brown dwarf known as WISE 0855, located 7.2 light-years away from us. Discovered two years ago, Brown dwarf WISE 0855 is the coldest heavenly body known to exist beyond our solar system, with a temperature of –23 degrees Celsius. It is to be noted that it is not a planet; it is described as being a “failed star” because it is not a star either. Scientists think such objects fall in between the definitions of planets and stars. While their formation is similar to that of stars, they cannot shine like the latter because of the lack of mass to fuel the required nuclear reactions.
While WISE 0855 is otherwise difficult to view, the team of researchers led by astronomer Andrew Skemer from the University of California have been successful at obtaining an infrared spectrum thereof by using the Hawaii-based Gemini-North telescope.
“Now that we have a spectrum, we can really start thinking about what’s going on in this object. Our spectrum shows that WISE 0855 is dominated by water vapour and clouds, with an overall appearance that is strikingly similar to Jupiter,” says Skemer.
Given its very low temperature, scientists were expecting the presence of water clouds in its vicinity. The new study, therefore, constitutes compelling evidence. It is hoped that the finding will help researchers gain a better understanding of such extrasolar bodies, and of planets like Jupiter, which is a giant gas one. This is so because the brown dwarf is thought to be quite similar to Jupiter in spite of the great difference in temperature (Jupiter is much colder, at –143 degrees Celsius).
“WISE 0855 is our first opportunity to study an extrasolar planetary-mass object that is nearly as cold as our own gas giants,” notes Skemer.
“The spectrum allows us to investigate dynamical and chemical properties that have long been studied in Jupiter’s atmosphere, but this time on an extrasolar world,” said Skemer.33
The findings are also published in The Astrophysical Journal Letters.