Mass Production of 2021 KMTNet Microlensing Planets III: Analysis of Three Giant Planets

TL;DR

This paper analyzes three giant planets discovered via microlensing in 2021, highlighting the importance of by-eye detection methods and their role in understanding planet populations around low-mass stars.

Contribution

It presents detailed analysis of three new microlensing planets, including a case detected by-eye but not by algorithm, emphasizing the value of manual detection in exoplanet surveys.

Findings

Detection of three giant planets around low-mass stars.

Identification of a planet found by-eye but missed by algorithms.

Evidence of diverse planet populations around very-low-mass hosts.

Abstract

We present the analysis of three more planets from the KMTNet 2021 microlensing season. KMT-2021-BLG-0119Lb is a $\sim 6\, M_{\rm Jup}$ planet orbiting an early M-dwarf or a K-dwarf, KMT-2021-BLG-0192Lb is a $\sim 2\, M_{\rm Nep}$ planet orbiting an M-dwarf, and KMT-2021-BLG-0192Lb is a $\sim 1.25\, M_{\rm Nep}$ planet orbiting a very--low-mass M dwarf or a brown dwarf. These by-eye planet detections provide an important comparison sample to the sample selected with the AnomalyFinder algorithm, and in particular, KMT-2021-BLG-2294, is a case of a planet detected by-eye but not by-algorithm. KMT-2021-BLG-2294Lb is part of a population of microlensing planets around very-low-mass host stars that spans the full range of planet masses, in contrast to the planet population at $\lesssim 0.1\, $ au, which shows a strong preference for small planets.