Gliese 581
Vogt's group of astronomers said that they have found two more planets orbiting Gliese 581, named 581f and 581g.  They published their findings in 2010.  For planet 581f, they found a mass of 7.0 Earth masses and an orbit length of 433 days.  For the other new planet, 581g, the group measured a mass that was 3.1 times the mass of the Earth and an orbit that was 36.6 days long.