OGLE-2015-BLG-0051/KMT-2015-BLG-0048Lb: a Giant Planet Orbiting a Low-mass Bulge Star Discovered by High-cadence Microlensing Surveys

TL;DR

This paper reports the discovery of a giant planet orbiting a low-mass star in the Galactic bulge through high-cadence microlensing surveys, demonstrating the effectiveness of current methods in detecting such exoplanets.

Contribution

It presents a new exoplanet discovery using dense, high-cadence microlensing data and Bayesian analysis to determine the host star's location and properties.

Findings

Planet mass approximately 0.72 Jupiter masses

Host star is a low-mass M-dwarf in the Galactic bulge

Planet's projected separation is about 0.73 AU

Abstract

We report the discovery of an extrasolar planet detected from the combined data of a microlensing event OGLE-2015-BLG-0051/KMT-2015-BLG-0048 acquired by two microlensing surveys. Despite that the short planetary signal occurred in the very early Bulge season during which the lensing event could be seen for just about an hour, the signal was continuously and densely covered. From the Bayesian analysis using models of the mass function, matter and velocity distributions combined with the information of the angular Einstein radius, it is found that the host of the planet is located in the Galactic bulge. The planet has a mass $0.72_{-0.07}^{+0.65}\ M_{\rm J}$ and it is orbiting a low-mass M-dwarf host with a projected separation $d_\perp=0.73 \pm 0.08$ AU. The discovery of the planet demonstrates the capability of the current high-cadence microlensing lensing surveys in detecting and characterizing planets.