According to astronomers, it is one of the most unusual astronomical discoveries EVER.
First sighted in 2014, WISE 0855 is a brown dwarf and is the coldest known object astronomers have spotted sitting just outside our solar system. The object is barely visible at infrared wavelengths using the largest ground-based telescopes on our planet.
Even though it’s hard to spot in the sky, astronomers made a sensational discovery as they have found the existence of clouds of water or water ice.
The team was led by scientists at UC Santa Cruz who succeeded in obtaining an infrared spectrum of WISE 0855 with the aid of the Gemini North Telescope in Hawaii, which allowed them to obtain the first details of the objects composition and chemistry.
According to the results, the finding offers substantial evidence of the existence of clouds of water or water ice,m the first of such clouds ever to be discovered outside of our solar system.
Andrew Skemer, assistant professor of astronomy and astrophysics at UC Santa Cruz said: ‘We would expect an object that cold to have water clouds, and this is the best evidence that it does.’
Astronomers have discovered that the conditions on the brown star as extremely similar to those on Jupiter. WISE 0855 has a mass five times that of Jupiter and resembles the gas giant in a number of ways.
According to astronomers, its temperature is around 250 degrees Kelvin, or -10 degrees Fahrenheit, which means that it is very similar in temperature to Jupiter, which is 130 degrees, Kelvin.
‘WISE 0855 is our first opportunity to study an extrasolar planetary-mass object that is nearly as cold as our own gas giants,’ Skemer said.
A number of studies published in 2014 offered tentative indications of water clouds, but data was limited.
Andrew Skemer, a coauthor of earlier studies, said that getting a spectrum is the only way we are able to understand the molecular composition of the object.
WISE 0855 is too faint to be studied with conventional spectroscopy at optical or near-infrared wavelengths, but thermal emission from the deep atmosphere at wavelengths in a narrow window around 5 microns offered an opportunity where spectroscopy would be ‘challenging but not impossible, said Skemer.
The group of astronomers used the Gemini-North telescope located in Hawaii and the Gemini Near Infrared Spectrograph to spy on WISE 0855 for nearly two weeks for a total of around 14 observational hours.
The results are fascinating:
‘It’s five times fainter than any other object detected with ground-based spectroscopy at this wavelength,’ Skemer said.
‘Now that we have a spectrum, we can actually start thinking about what’s going on in this object.
‘Our spectrum shows that WISE 0855 is dominated by water vapor and clouds, with an overall appearance that is strikingly similar to Jupiter.’
Interestingly, when researchers compared the brown dwarf to Jupiter, they found that their spectra are very similar with respect to water absorption features.
The research will be published in the Astrophysical Journal Letters.