The MicroFUN Collaboration, in conjunction with the OLGE and PLANET/RoboNet collaborations, are pleased to report the discovery of a Neptune-mass "Super-Earth" planetary companion of the lensing star in the extremely high-magnification microlensing event OGLE-2005-BLG-169. If the parent star is a Main-Sequence star, it would have a mass of 0.5Msun, implying a planet mass of ~13Mearth and a projected separation of ~2.7AU. This is the second Neptune-mass planet found via microlensing (the other was OGLE-2005-BLG-390; Beaulieu et al. 2006), implying that such "Cool Neptune" planets may be relatively common, with frequency of &16% at 90% confidence.
This is the fourth planet discovered using the Microlensing technique, and the second found by the MicroFUN collaboration, the other being OGLE-2005-BLG-071, a Jupiter-mass planet announced in May 2005.