From Sky & Telescope
LOW-MASS EXOPLANET
Three international groups have teamed up to discover what is probably the
lowest-mass planet ever found around a normal star. The planet's mass is
between 3 and 11 times that of Earth, with a most likely mass of 5.5
Earths. The previous record-holder, which orbits the red-dwarf star Gliese
876, contains about 7.5 Earth masses. The only known exoplanets with lower
masses are four objects orbiting a pulsar -- the collapsed core of a
massive star that went supernova....
http://SkyandTelescope.com/news/article_1667_1.asp