2MASS J12073346-3932539 is a young brown dwarf in the TW Hydrae association. 2M1207 b was the first planetary-mass companion ever imaged directly, a wide young object orbiting a brown dwarf. 2MASS J12073346-3932539 b is a 5.20-Jupiter-mass companion, and an equilibrium temperature near 1,163 K, discovered in 2004 via direct imaging. Direct imaging revealed these planets because they are young, massive, and widely separated from their star, appearing bright in infrared light against the glare. The planet's large radius (15.7 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation. With an equilibrium temperature around 1,163 K, the dayside atmosphere is hot enough to vaporise many common minerals.