Astronomers have always thought that objects with the mass of planets orbit stars, or failed stars, know as brown dwarfs. Now a discovery by a team led by a University of Toronto researcher, Ray Jayawardhana, has shown otherwise.
The team's discovery of a seven-Jupiter-mass companion next to a planetary mass object, only twice its mass. Both objects have masses similar to those of extra-solar giant planets, usually found in orbit around a star. Unexpectedly, these bodies appear to circle each other.
The team discovered the companion candidate in an optical image taken with the European Southern Observatory’s 3.5-meter New Technology Telescope on La Silla, Chile, and investigated it further with optical spectra and infrared images obtained with ESO’s 8.2-meter Very Large Telescope on Paranal, Chile. These followup observations confirmed that both objects are young, at the same distance, and much too cool to be stars. The existence of this wide pair poses a challenge to a popular theory which suggests that brown dwarfs and planemos are embryos ejected from multiple proto-star systems.