OGLE-2019-BLG-0468Lb,c: two microlensing giant planets around a G-type star

TL;DR

This paper reports the discovery of a multi-planet system around a G-type star via microlensing, revealing a triple-lens interpretation that explains complex anomaly features in the light curve.

Contribution

It presents the first secure microlensing detection of a three-planet system with detailed modeling of complex anomalies.

Findings

Two giant planets with masses ~3.4 and ~10.2 M_Jupiter

The host star is a G-type star of ~0.9 solar masses

The system is located about 4.4 kpc away from Earth

Abstract

With the aim of interpreting anomalous lensing events with no suggested models, we conducted a project of reinvestigating microlensing data in and before the 2019 season. In this work, we report a multi-planet system OGLE-2019-BLG-0468L found from the project. The light curve of the lensing event OGLE-2019-BLG-0468, which consists of three distinctive anomaly features, could not be explained by the usual binary-lens or binary-source interpretation. We find a solution explaining all anomaly features with a triple-lens interpretation, in which the lens is composed of two planets and their host, making the lens the fourth multi-planet system securely found by microlensing. The two planets have masses $\sim 3.4~M_{\rm J}$ and $\sim 10.2~M_{\rm J}$, and they are orbiting around a G-type star with a mass $\sim 0.9~M_\odot$ and a distance $\sim 4.4$ kpc. The host of the planets is most likely responsible for the light of the baseline object, although the possibility for the host to be a companion to the baseline object cannot be ruled out.