Astronomers find planet that isn’t orbiting a star

BBC : Located just 100 light-years away, this new “rogue” planet is the first such discovery in close proximity to Earth. Etienne Artigau of the University of Montreal led an international team that scanned the nearby sky in the IR using the Canada-France-Hawaii Telescope on Hawaii’s Mauna Kea and the Very Large Telescope in Chile. The planet they found appears to be among a cluster of about 30 stars that are all moving in the same direction, though the planet is not orbiting any of them. Because of the ages of the star cluster, Artigau’s group believes that the planet itself is only 50â120 million years old. Based on the data they collected, planet formation models suggest that the planet is between four and seven times the mass of Jupiter and has a surface temperature of 400 °C. Artigau’s group does not know if the planet was ejected from orbit around one of the stars or if it formed separately but did not collect enough material to become a star itself.