Researchers from the Université de Montréal and the European Organization for Astronomical Research (ESO) have discovered a homeless, free-floating planet known as CFBDSIR2149. Although the existence of such planets has been theorized, this planet — which is just 100 light-years away from our solar system — is the first without any gravitional tie to a star to be observed. The planet lies within the AB Doradus Moving Group, a cluster of young, free-floating stars. Prior to this discovery, researchers were unsure if the group contained any planets or just brown dwarfs, which are failed stars.
The researchers were able to study CFBDSIR2149 in greater detail because there is no nearby sun to interfere with their observations. They found that the planet is between 50 and 120 million years old, has a temperature of about 400 degrees Celsius, and has a mass about four to seven times the size of Jupiter — this distinguishes it from brown dwarfs, which have at least 13 times the mass of Jupiter. Researchers say this discovery will help them better observe and understand exoplanets that do orbit stars, and supports the theory that there may be many more of these free-floating objects than previously thought.