2015ApJ...799..237U

We combine Spitzer and ground-based observations to measure the microlens parallax vector π_E, and thus the mass and distance of OGLE-2014-BLG-0124L, making it the first microlensing planetary system with a space-based parallax measurement. The planet and star have masses of m ∼ 0.5 M_jup and M ∼ 0.7 M_☉and are separated by a∼ 3.1 AU in projection. The main source of uncertainty in all of these numbers (approximately 30%, 30%, and 20%) is the relatively poor measurement of the Einstein radius θ_E, rather than uncertainty in π_E, which is measured with 2.5% precision. This compares to 22% based on OGLE data alone, implying that the Spitzer data provide not only a substantial improvement in the precision of the π_Emeasurement, but also the first independent test of a ground-based π_E measurement.