Astronomers have found the first object outside the solar system with clouds of water in its atmosphere. The object named WISE 0855- a brown dwarf which lies 7.2 light-years from Earth- is the coldest extrasolar “failed star” ever discovered.
In 2014, astronomer Kevin Luhman of Penn State University found the brownish object by using data from NASA’s Wide-field Infrared Survey Explorer (WISE) spacecraft.
By basing his research on limited photometric data- a system of filters that recognizes radiation of object is in specific light wavelengths, Andrew Skemer – assistant professor of astronomy and astrophysics at the University of California in Santa Cruz discovered evidence of water clouds in the atmosphere of extrasolar dwarf WISE 0855.
“We would expect an object that cold to have water clouds, and this is the best evidence that it does,” said and lead author of the research Andrew Skemer, published in the journal Astrophysical Journal Letters.
WISE 0855 a dwarf very similar to Jupiter
Even though WISE 0855 is considered a “failed start” because of its dimensions (too great to be a planet but too small to be a start), right now scientist are discussing over that term. Since it only has five times the mass of Jupiter, this “dwarf” is still considered small.
In 2014, WISE 0855 was known in the past for being the fourth closest object to the solar system, but from now on scientist will refer to it as the object that shares more similar properties with Jupiter than any other extrasolar planet.
In regards to similarities to Jupiter, the spectrum showed that the brown dwarf have significant similar water absorption characteristics to Jupiter, but it lacks phosphine, which is an indicative of turbulent atmospheres like Jupiter’s. According to astronomers, WISE 0855 would be useful to hope better to use WISE 0855 to study the gas giant planet Jupiter better.
Since WISE 0855 discovery, scientist believed that this brownish world was likely to have water clouds in its atmosphere. Therefore they traveled to Hawaii’s Mauna Kea to use the Gemini North telescope and obtain the first light fingerprint” for WISE 0855.
The spectroscopy provided significant evidence of water clouds in WISE 0855
Over 13 night and a period of 14 hours of data gathering, scientists used Gemini North facilities to get a spectrum that could provide enough evidence to determine the properties of the brownish dwarf.
According to Skemer, with the new spectrum, scientists can study what is inside the extrasolar object. He says that the spectrum showed enough evidence that WISE 0855 is a gaseous object plenty of water and vapor cloud, which is striking similar to the characteristics of our giant Jupiter.
The findings obtained by the spectrum were possible thanks to the location of Gemini North telescope. Jacqueline Faherty -astronomer from the Carnegie Department of Terrestrial Magnetism- said in a press release that Mauna Kea is the perfect place to get a spectrum of WISE 0855.
“These observations could only be done on a facility like Gemini North. This is due to its location on Maunakea, where there is often remarkably little water vapor in the air to interfere with the sensitive observations, and the technology on the telescope, like its 8-meter silver-coated mirror,”she added.
Therefore, the team took advantage of such conditions and made the most of Gemini North telescope here on Earth. She says that the findings were spectacular for science.
The spectrum not only unveiled the water clouds of WISE 0855 but also confirmed that this brown dwarf has a freezing temperature that ranges below -10 degrees Fahrenheit.
For Skemer, everyone on the dwarf research did not know for sure if they were going to get a spectrum of the brown extrasolar object because its glow was not so shining. Also, the WISE 0855, is not so visible that many astronomers of the research believed that it would take them many years before they could actually dissect the tiny light into a spectrum. Therefore, the lead author Skemer thought that we would have to wait for the opening of James Webb Space Telescope to get the so wanted spectrum.
Spectroscopy: a useful tool to find spatial body’s molecular composition
This experience made Skemer confirm that with spectroscopy astronomers can separate the light of a space body into a wide range of infrared wavelengths, probing what is the molecular composition of dwarfs, planets, and all kinds of bodies.
He says that if humans were able to see infrared light, which is a lot redder than the red light we can see, the information obtained would look like the colors of a rainbow because the relative brightness of each would show us some insights about the atmosphere and the object’s environment.
For Skemer this spectrum is crucial because it would allow astronomers to study in depth about the dynamical and chemical properties that have already been considered in Jupiter’s atmosphere and also in any other extrasolar bodies.