In 2009 it was announced that GJ 1214, a star in Ophiuchus, undergoes repeated, cyclical dimming with a period of about 1. 5 days consistent with the transit of a small orbiting planet.

If a planet is sufficiently massive, the water on it may be solid even at high temperatures, because of the high pressure caused by gravity, as it was observed on exoplanets Gliese 436 b and GJ 1214 b.

* The GJ 1214 b's average distance from the star GJ 1214 is 2. 14 Gm, which is the smallest orbit of any known exoplanets.