Gliese 436 b (GJ 436 b) is an exoplanet the size of Neptune, orbiting the red dwarf star Gliese 436.It was discovered in 2004, and was the first extrasolar planet on which it was determined to contain water.

It is the smallest planet known to have transits with its star. Perturbations have been measured in its orbit, and are thought to be caused by another smaller planet, which has been named Gliese 436 c.


Observations of GJ436b

Collaborative projects