Characterizing microlensing planetary system OGLE-2014-BLG-0676Lb with adaptive optics imaging

TL;DR

This study uses adaptive optics imaging to characterize the host star and planetary properties of the microlensing planet OGLE-2014-BLG-0676Lb, providing new constraints on its mass, distance, and separation.

Contribution

First direct measurement of the host star flux for OGLE-2014-BLG-0676Lb using AO imaging, refining planetary and host star parameters in a microlensing event.

Findings

Host star is a ~0.73 M_Sun star at ~2.67 kpc.

Planet has a mass of ~3.7 M_J and is a super-Jupiter.

Results are consistent with Bayesian Galactic model estimates.

Abstract

We constrain the host-star flux of the microlensing planet OGLE-2014-BLG-0676Lb using adaptive optics (AO) images taken by the Magellan and Keck telescopes. We measure the flux of the light blended with the microlensed source to be K = 16.79 +/- 0.04 mag and J = 17.76 +/- 0.03 mag. Assuming that the blend is the lens star, we find that the host is a $0.73_{-0.29}^{+0.14}$ M_Sun star at a distance of $2.67_{-1.41}^{+0.77}$ kpc, where the relatively large uncertainty in angular Einstein radius measurement is the major source of uncertainty. With mass of $M_p = 3.68_{-1.44}^{+0.69}$ M_J, the planet is likely a "super Jupiter" at a projected separation of $r_{\perp} = 4.53_{-2.50}^{+1.49}$ AU, and a degenerate model yields a similar $M_p = 3.73_{-1.47}^{+0.73}$ M_J at a closer separation of $r_{\perp} = 2.56_{-1.41}^{+0.84}$ AU. Our estimates are consistent with the previous Bayesian analysis based on a Galactic model. OGLE-2014-BLG-0676Lb belongs to a sample of planets discovered in a "second-generation" planetary microlensing survey, and we attempt to systematically constrain host properties of this sample with high-resolution imaging to study the distribution of planets.