Spitzer as a Microlens Parallax Satellite: Mass Measurement for the OGLE-2014-BLG-0124L Planet and its Host Star

February 2015 • 2015ApJ...799..237U

Authors • Udalski, A. • Yee, J. C. • Gould, A. • Carey, S. • Zhu, W. • Skowron, J. • Kozłowski, S. • Poleski, R. • Pietrukowicz, P. • Pietrzyński, G. • Szymański, M. K. • Mróz, P. • Soszyński, I. • Ulaczyk, K. • Wyrzykowski, Ł. • Han, C. • Calchi Novati, S. • Pogge, R. W.

Abstract • We combine Spitzer and ground-based observations to measure the microlens parallax vector {\boldsymbol {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 θE, rather than uncertainty in πE, 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 πE measurement, but also the first independent test of a ground-based {\boldsymbol {π }}_E measurement.


IPAC Authors


Sebastiano Calchi Novati

Associate Scientist

Sean Carey

Senior Scientist