Discovery and Characterization of the Most Jupiter-like Exoplanet Yet

Discovery image of 51 Eri b with the Gemini Planet Imager taken in the near-infrared light on December 18, 2014. The bright central star has been mostly removed by a hardware and software mask to enable the detection of the exoplanet one million times fainter. Credits: J. Rameau (UdeM) and C. Marois (NRC Herzberg).

Astronomers have used the Gemini Planet Imager (GPI) on Gemini South to discover and characterize the most Jupiter-like planet ever found outside of the Solar System. Bruce Macintosh (Stanford University) and collaborators report in the journal Science of a planet likely having only twice the mass of Jupiter, with the strongest spectral signature of methane ever seen in the atmosphere of an exoplanet. The planet, a companion to the star 51 Eridani, is the lowest-mass self-luminous planet ever directly imaged. See the Gemini press release or full report in Science (subscription required).