Systematic KMTNet Planetary Anomaly Search, Paper II: Six New $q<2\times 10^{-4}$ Mass-ratio Planets

Abstract

We apply the automated AnomalyFinder algorithm of Paper I (Zang et al. 2021b) to 2018-2019 light curves from the $\simeq 13{\mathrm{deg}}^2$ covered by the six KMTNet prime fields, with cadences $\Gamma \ge 2{\mathrm{hr}}^{-1}$. We find a total of 11 planets with mass ratios $q<2\times 10^{-4}$, including six newly discovered planets, one planet that was reported in Paper I, and recovery of four previously discovered planets. One of the new planets, OGLE-2018-BLG-0977Lb, is in a planetary-caustic event, while the other five (OGLE-2018-BLG-0506Lb, OGLE-2018-BLG-0516Lb, OGLE-2019-BLG-1492Lb, KMT-2019-BLG-0253, and KMT-2019-BLG-0953) are revealed by a "dip" in the light curve as the source crosses the host-planet axis on the opposite side of the planet. These subtle signals were missed in previous by-eye searches. The planet-host separations (scaled to the Einstein radius), $s$, and planet-host mass ratios, $q$, are, respectively, $(s,q\times 10^5)=(0.88,4.1)$, $(0.96\pm 0.10,8.3)$, $(0.94\pm 0.07,13)$, $(0.97\pm 0.07,18)$, $(0.97\pm 0.04,4.1)$, and $(0.74,18)$, where the "$\pm$" indicates a discrete degeneracy. The 11 planets are spread out over the range $-5<\log q<-3.7$. Together with the two planets previously reported with $q\sim 10^{-5}$ from the 2018-2019 non-prime KMT fields, this result suggests that planets toward the bottom of this mass-ratio range may be more common than previously believed.

arXiv comment58 pages, 9 figures, 12 tables, submitted to AJ

References in corpus (56)

• emcee: The MCMC Hammer
• A method for optimal image subtraction
• Discovery of a Cool Planet of 5.5 Earth Masses Through Gravitational Microlensing
• Reddening and Extinction Toward the Galactic Bulge from OGLE-III: The Inner Milky Way's Rv ~ 2.5 Extinction Curve
• Real-Time Difference Imaging Analysis of MOA Galactic Bulge Observations During 2000
• Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. V. Evidence for a wide age distribution and a complex MDF
• The angular size of dwarf stars and subgiants - Surface brightness relations calibrated by interferometry
• OGLE-2003-BLG-262: Finite-Source Effects from a Point-Mass Lens
• OGLE 2003-BLG-235/MOA 2003-BLG-53: A planetary microlensing event
• Frequency of Solar-Like Systems and of Ice and Gas Giants Beyond the Snow Line from High-Magnification Microlensing Events in 2005-2008
• Microlens OGLE-2005-BLG-169 Implies Cool Neptune-Like Planets are Common
• The Exoplanet Mass-Ratio Function from the MOA-II Survey: Discovery of a Break and Likely Peak at a Neptune Mass
• Expanding the Realm of Microlensing Surveys with Difference Image Photometry
• A Natural Formalism for Microlensing
• Difference imaging photometry of blended gravitational microlensing events with a numerical kernel
• Resolution of the MACHO-LMC-5 Puzzle: The Jerk-Parallax Microlens Degeneracy
• The Luminosity Function and Mass Function in the Galactic Bulge
• A Cold Neptune-Mass Planet OGLE-2007-BLG-368Lb: Cold Neptunes Are Common
• OGLE-2005-BLG-071Lb, the Most Massive M-Dwarf Planetary Companion?
• Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
• MOA-2009-BLG-387Lb: A massive planet orbiting an M dwarf
• First microlens mass measurement: PLANET photometry of EROS BLG-2000-5
• Planet Parameters in Microlensing Events
• Korea Microlensing Telescope Network Microlensing Events from 2015: Event-Finding Algorithm, Vetting, and Photometry
• Properties of Planetary Caustics in Gravitational Microlensing
• Microlensing with advanced contour integration algorithm: Green's theorem to third order, error control, optimal sampling and limb darkening
• Acceleration and Parallax Effects in Gravitational Microlensing
• Microlensing Constraints on the Frequency of Jupiter-Mass Companions: Analysis of Five Years of PLANET Photometry
• Theory of Pixel Lensing
• An Earth-mass Planet in a 1-AU Orbit around an Ultracool Dwarf
• VBBinaryLensing: a public package for microlensing light curve computation
• The Lowest Mass Ratio Planetary Microlens: OGLE 2016-BLG-1195Lb
• MOA 2003-BLG-37: A Bulge Jerk-Parallax Microlens Degeneracy
• Systematic KMTNet Planetary Anomaly Search, Paper I: OGLE-2019-BLG-1053Lb, A Buried Terrestrial Planet
• OGLE-2018-BLG-0567Lb and OGLE-2018-BLG-0962Lb: Two Microlensing Planets through Planetary-Caustic Channel
• Keck Observations Confirm a Super-Jupiter Planet Orbiting M-dwarf OGLE-2005-BLG-071L
• Potential Direct Single-Star Mass Measurement
• KMT-2017-BLG-0165Lb: A Super-Neptune mass planet Orbiting a Sun-like Host Star
• OGLE-2018-BLG-1011L\lowercase{b,c}: Microlensing Planetary System with Two Giant Planets Orbiting a Low-mass Star
• OGLE-2018-BLG-1700L: Microlensing Planet in Binary Stellar System
• Properties of the Planetary Caustic Perturbation
• Microlens Masses from 1-D Parallaxes and Heliocentric Proper Motions
• OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observation
• Ogle-2018-blg-0677lb: A super earth near the galactic bulge
• Spitzer Microlensing Parallax for OGLE-2016-BLG-1067: a sub-Jupiter Orbiting an M-dwarf in the Disk
• Measurement of Source Star Colors with the K2C9-CFHT Multi-color Microlensing Survey
• Three microlensing planets with no caustic-crossing features
• Properties of stream interaction regions at Earth and Mars during the declining phase of SC 24
• $Spitzer$ Parallax of OGLE-2018-BLG-0596: A Low-mass-ratio Planet around an M-dwarf
• OGLE-2018-BLG-0532Lb: Cold Neptune With Possible Jovian Sibling
• One Planet or Two Planets? The Ultra-sensitive Extreme-magnification Microlensing Event KMT-2019-BLG-1953
• KMT-2019-BLG-0842Lb: A Cold Planet Below the Uranus/Sun Mass Ratio
• KMT-2019-BLG-1715: planetary microlensing event with three lens masses and two source stars
• OGLE-2015-BLG-1670Lb: A Cold Neptune beyond the Snow Line in the Provisional WFIRST Microlensing Survey Field
• KMT-2019-BLG-0371 and the Limits of Bayesian Analysis
• OGLE-2018-BLG-1269Lb: A Jovian Planet With A Bright, $I=16$ Host

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• Mass Production of 2021 KMTNet Microlensing Planets III: Analysis of Three Giant Planets
• 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
• MOA-2022-BLG-249Lb: Nearby microlensing super-Earth planet detected from high-cadence surveys
• OGLE-2016-BLG-1093Lb: A Sub-Jupiter-mass Spitzer Planet Located in Galactic Bulge
• OGLE-2015-BLG-1609Lb: Sub-jovian planet orbiting a low-mass stellar or brown dwarf host
• Earth-like planet predictor: A machine learning approach
• KMT-2021-BLG-1150Lb: Microlensing planet detected through a densely covered planetary-caustic signal
• KMT-2018-BLG-1988Lb: microlensing super-Earth orbiting a low-mass disk dwarf
• OGLE-2019-BLG-0468Lb,c: two microlensing giant planets around a G-type star