Friday, June 10, 2016

Microlensing Detection of a Saturn-Like Planet

OGLE-2014-BLG-1760 is a gravitational microlensing event involving a star with 0.51 ± 0.44 times the mass of the Sun that hosts a planet with 180 ± 110 times the mass of Earth. Both the star and its planet were detected when they crossed the line-of-sight to a background star, and their combined gravitational fields acted as a “lens”, magnifying the brightness of the background star. Assuming the planetary system is 22.5 ± 3.6 thousand light years away, the projected star-planet separation will be 1.7 ± 0.3 AU. From its estimated mass, this planet is probably a low mass gas giant planet like Saturn. Since both the star and its planet have a high proper motion relative to the background star, they are expected to become resolvable in the near future when their angular separation is larger, allowing the properties of the planetary system to be better determined.

Bhattacharya et al. (2016), “Discovery of a Gas giant Planet in Microlensing Event OGLE-2014-BLG-1760”, arXiv:1603.05677 [astro-ph.EP]