Systematic KMTNet Planetary Anomaly Search, Paper III: One Wide-Orbit Planet And Two Stellar Binaries

Abstract

Only a few wide-orbit planets around old stars have been detected, which limits our statistical understanding of this planet population. Following the systematic search for planetary anomalies in microlensing events found by the Korea Microlensing Telescope Network (KMTNet), we present the discovery and analysis of three events that were initially thought to contain wide-orbit planets. The anomalous feature in the light curve of OGLE-2018-BLG-0383 is caused by a planet with mass ratio $q=2.1\times 10^{-4}$ and a projected separation $s=2.45$. This makes it the lowest mass-ratio microlensing planet at such wide orbits. The other two events, KMT-2018-BLG-0998 and OGLE-2018-BLG-0271, are shown to be stellar binaries ($q>0.1$) with rather close ($s<1$) separations. We briefly discuss the properties of known wide-orbit microlensing planets and show that the survey observations are crucial in discovering and further statistically constraining such a planet population.

Accepted by MNRAS

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• Systematic KMTNet Planetary Anomaly Search, Paper VII: Complete Sample of $q<10^{-4}$ Planets from the First Four-Year Survey
• Mass Production of 2021 KMTNet Microlensing Planets I
• Systematic KMTNet Planetary Anomaly Search. VIII. Complete Sample of 2019 Subprime Field Planets
• OGLE-2019-BLG-1470LABc: Another Microlensing Giant Planet in a Binary System?
• Systematic Reanalysis of KMTNet Microlensing Events, Paper II: Two New Planets in Giant-Source Events
• Systematic KMTNet Planetary Anomaly Search. XII. Complete Sample of 2017 Subprime Field Planets
• KMT-2017-BLG-0673Lb and KMT-2019-BLG-0414Lb: Two microlensing planets detected in peripheral fields of KMTNet survey
• Exoplanet Occurrence Rates from Microlensing Surveys
• Mass Production of 2021 KMTNet Microlensing Planets II
• MAGIC: Microlensing Analysis Guided by Intelligent Computation
• MOA-2020-BLG-208Lb: Cool Sub-Saturn Planet Within Predicted Desert
• OGLE-2015-BLG-1609Lb: Sub-jovian planet orbiting a low-mass stellar or brown dwarf host
• Binary-lens Microlensing Degeneracy: Impact on Planetary Sensitivity and Mass-ratio Function