Astronomers discover ‘rogue’ planet drifting through space

14 Nov 2012

Artist's impression of the free-floating CFBDSIR2149 planet. Image via European Space Observatory

Astronomers are claiming to have found a free-floating planet some 100 light years away that’s wandering alone through space without a parent star. Such planets are dubbed rogue or nomad planets because they do not orbit a star.

The free-floating planet has been labelled CFBDSIR2149 by the scientists who discovered it. Their findings have been published in Astronomy and Astrophysics.

The researchers said they found the planet based on observations from the European Space Observatory’s (ESO) Very Large Telescope, which is based in the Atacama Desert in northern Chile, and the Canada-France-Hawaii Telescope, based on the summit of Mauna Kea in Hawaii.

The astrophysicists involved in the study of the planetary object, who are from the University of Montreal, the Centre for Research in Astrophysics of Quebec and from the Laboratoire d’Astrophysique de l’Observatoire de Grenoble, believe it is between four and seven times bigger than Jupiter.

Wandering planet …

Because the free-floating planet does not have a bright star close to it, they said it allowed them to study the atmosphere of CFBDSIR2149 in greater detail.

According to the ESO, the planet appears to be part of a nearby stream of young stars known as the AB Doradus Moving Group, the closest such group to the solar system.

The ESO said this is the first isolated planetary mass object that has ever been identified in a moving group. It said rogue planets such as CFBDSIR2149 are thought to form either as normal planets that have been turfed out of their home systems, or as lone objects, like the smallest stars or brown dwarfs.

“These objects are important, as they can either help us understand more about how planets may be ejected from planetary systems, or how very light objects can arise from the star formation process,” said Philippe Delorme, the lead author of the study, who is based at Institut de planétologie et d’astrophysique de Grenoble.

“If this little object is a planet that has been ejected from its native system, it conjures up the striking image of orphaned worlds, drifting in the emptiness of space,” he said.

Delorme said further work should confirm that CFBDSIR2149 is a free-floating planet. He said the planet could be used as a benchmark for understanding the physics of any similar exoplanets that are found in the future.

This image captured by the SOFI instrument on ESO's New Technology Telescope shows the free-floating planet CFBDSIR J214947.2-040308.9 in infrared light. This object appears as a faint blue dot at the centre of the picture. Credit: ESO

This image captured by the SOFI instrument on ESO’s New Technology Telescope shows the free-floating planet CFBDSIR2149 in infrared light. This object appears as a faint blue dot at the centre of the picture. Image via ESO

Carmel Doyle was a long-time reporter with Silicon Republic