OGLE-2018-BLG-0567Lb and OGLE-2018-BLG-0962Lb: Two Microlensing Planets through the Planetary-caustic Channel

Abstract

We present the analyses of two microlensing events, OGLE-2018-BLG-0567 and OGLE-2018-BLG-0962. In both events, the short-lasting anomalies were densely and continuously covered by two high-cadence surveys. The light-curve modeling indicates that the anomalies are generated by source crossings over the planetary caustics induced by planetary companions to the hosts. The estimated planet/host separation (scaled to the angular Einstein radius θE) and mass ratio are (s, q × 10³) = (1.81 ± 0.02, 1.24 ± 0.07) and (s, q × 10³) = (1.25 ± 0.03, 2.38 ± 0.08), respectively. From Bayesian analyses, we estimate the host and planet masses as (M_h, M_p) = 0.25_(-0.13)^(+0.27) M_⊙, 0.32_(-0.17)^(+0.34) M_J) and (M_h, M_p) = (0.54_(-0.28)^(+0.33) M_⊙, 1.34_(-0.70)^(+0.82) M_J), respectively. These planetary systems are located at a distance of 7.06_(-1.15)^(+0.93) kpc for OGLE-2018-BLG-0567 and 6.50_(-1.75)^(+1.06) kpc for OGLE-2018-BLG-0962, suggesting that they are likely to be near the Galactic bulge. The two events prove the capability of current high-cadence surveys for finding planets through the planetary-caustic channel. We find that most published planetary-caustic planets are found in Hollywood events in which the source size strongly contributes to the anomaly cross-section relative to the size of the caustic.

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