In-Gu Shin
A5076860689- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- History and Developments in Astronomy
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- Space Exploration and Technology
- Galaxies: Formation, Evolution, Phenomena
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Spacecraft Design and Technology
- Astrophysical Phenomena and Observations
- Planetary Science and Exploration
- Impact of Light on Environment and Health
- Advanced Frequency and Time Standards
- Geochemistry and Geologic Mapping
- Optical Systems and Laser Technology
- Astrophysics and Cosmic Phenomena
- Earthquake Detection and Analysis
- GNSS positioning and interference
Center for Astrophysics Harvard & Smithsonian
2016-2024
Korea Astronomy and Space Science Institute
2016-2023
Chungbuk National University
2011-2023
Massey University
2023
Korea University of Science and Technology
2023
Tsinghua University
2023
The Ohio State University
2023
University of Canterbury
2023
Max Planck Institute for Astronomy
2018-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
2023
We present the first microlensing candidate for a free-floating exoplanet–exomoon system, MOA-2011-BLG-262, with primary lens mass of Mhost ∼ 4 Jupiter masses hosting sub-Earth moon. The argument an exomoon hinges on system being relatively close to Sun. data constrain product MLπrel where ML is and πrel lens–source relative parallax. If nearby (large πrel), then small (a few masses) companion sub-Earth-mass exomoon. best-fit solution has large proper motion, μrel = 19.6 ± 1.6 mas yr−1,...
Because of the development large-format, wide-field cameras, microlensing surveys are now able to monitor millions stars with sufficient cadence detect planets. These new discoveries will span full range significance levels including planetary signals too small be distinguished from noise. At present, we do not understand where threshold is for detecting MOA-2011-BLG-293Lb first planet published surveys, and it also has substantial follow-up observations. This robustly detected in...
Impolite planet ignores host's partner Many known exoplanets (planets outside our own solar system) are hosted by binary systems that contain two stars. These planets normally circle around both of their Using microlensing data taken with a worldwide network telescopes, Gould et al. found twice the mass Earth circles just one pair The same approach has potential to uncover other similar star and help illuminate some mysteries formation. Science , this issue p. 46
We combine $Spitzer$ and ground-based KMTNet microlensing observations to identify precisely measure an Earth-mass ($1.43^{+0.45}_{-0.32} M_\oplus$) planet OGLE-2016-BLG-1195Lb at $1.16^{+0.16}_{-0.13}$ AU orbiting a $0.078^{+0.016}_{-0.012} M_\odot$ ultracool dwarf. This is the lowest-mass date. At $3.91^{+0.42}_{-0.46}$ kpc, it third consecutive case among "Galactic distribution" planets toward Galactic bulge that lies in disk as opposed itself, hinting skewed distribution of planets....
We analyze an ensemble of microlensing events from the 2015 Spitzer campaign, all which were densely monitored by ground-based high-cadence survey teams. The simultaneous observations and ground yield measurements parallax vector $\pi_{\rm E}$, compact constraints on microlens properties are derived, including $\lesssim$25\% uncertainties lens mass distance. With current sample, we demonstrate that majority microlenses indeed in range M dwarfs. planet sensitivities 41 sample calculated,...
We report the discovery of a planetary system from observation high-magnification microlensing event OGLE-2012-BLG-0026. The lensing light curve exhibits complex central perturbation with multiple features. find that was produced by two planets located near Einstein ring planet host star. identify four possible solutions resulting well-known close/wide degeneracy. By measuring both lens parallax and radius, we estimate physical parameters system. According to best-fit model, masses are ∼0.11...
Observations of accretion disks around young brown dwarfs (BDs) have led to the speculation that they may form planetary systems similar normal stars. While there been several detections planetary-mass objects BDs (2MASS 1207-3932 and 2MASS 0441-2301), these companions relatively large mass ratios projected separations, suggesting formed in a manner analogous stellar binaries. We present discovery object orbiting field BD via gravitational microlensing, OGLE-2012-BLG-0358Lb. The system is...
We present the discovery of first Neptune analog exoplanet or super-Earth with Neptune-like orbit, MOA-2013-BLG-605Lb. This planet has a mass similar to that and it orbits at $9\sim 14$ times expected position snow-line, $a_{\rm snow}$, which is Neptune's separation $ 11\,a_{\rm snow}$ from Sun. The planet/host-star ratio $q=(3.6\pm0.7)\times 10^{-4}$ projected normalized by Einstein radius $s=2.39\pm0.05$. There are three degenerate physical solutions two these due new type degeneracy in...
We report the first mass and distance measurement of a caustic-crossing binary system OGLE-2014-BLG-1050L using space-based microlens parallax method. \emph{Spitzer} captured second event, which occurred $\sim$10 days before that seen from Earth. Due to coincidence source-lens relative motion was almost parallel direction binary-lens axis, four-fold degeneracy, known only occur in single-lens events, persists this case, leading either lower-mass (0.2 $M_\odot$ 0.07 $M_\odot$) at $\sim$1.1...
We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with planet–star mass ratio . Intensive photometric observations high-magnification event allow us to detect clear signal planet. Although no parallax is detected in light curve, we instead succeed at detecting flux from host star high-resolution JHK'-band images obtained by Subaru/AO188 and Infrared Camera Spectrograph instruments, allowing constrain absolute physical parameters planetary system. With help...
Planet formation theories predict the existence of free-floating planets that have been ejected from their parent systems. Although they emit little or no light, can be detected during gravitational microlensing events. Microlensing events caused by rogue are characterized very short timescales $t_{\rm E}$ (typically below two days) and small angular Einstein radii $\theta_{\rm (up to several uas). Here we present discovery characterization ultra-short identified in data Optical...
Abstract We report the discovery of a giant planet in OGLE-2017-BLG-1522 microlensing event. The planetary perturbations were clearly identified by high-cadence survey experiments despite relatively short event timescale t E ∼ 7.5 days. Einstein radius is unusually small, θ = 0.065 mas, implying that lens system either has very low mass or lies much closer to microlensed source than Sun, both. A Bayesian analysis yields component masses and source-lens distance , this brown-dwarf/Jupiter...
Some low-mass planets are expected to be ejected from their parent planetary systems during early stages of system formation. According planet-formation theories, such as the core accretion theory, typical masses should between 0.3 and 1.0 $M_{\oplus}$. Although in practice objects do not emit any light, they may detected using gravitational microlensing via light-bending gravity. Microlensing events due terrestrial-mass rogue have extremely small angular Einstein radii (< 1 uas) short...
Abstract In order to exhume the buried signatures of “missing planetary caustics” in Korea Microlensing Telescope Network (KMTNet) data, we conducted a systematic anomaly search residuals from point-source point-lens fits, based on modified version KMTNet EventFinder algorithm. This revealed lowest-mass-ratio caustic date microlensing event OGLE-2019-BLG-1053, for which signal had not been noticed before. The system has planet–host mass ratio q = (1.25 ± 0.13) × 10 −5 . A Bayesian analysis...
Abstract We apply the automated AnomalyFinder algorithm of Paper I to 2018–2019 light curves from ≃13 deg 2 covered by six KMTNet prime fields, with cadences Γ ≥ hr −1 . find a total 11 planets mass ratios q < × 10 −4 , including 6 newly discovered planets, 1 planet that was reported in I, and recovery 4 previously planets. One new OGLE-2018-BLG-0977Lb, is planetary caustic event, while other five (OGLE-2018-BLG-0506Lb, OGLE-2018-BLG-0516Lb, OGLE-2019-BLG-1492Lb, KMT-2019-BLG-0253,...
ABSTRACT We report the complete statistical planetary sample from prime fields (Γ ≥ 2 h−1) of 2019 Korea Microlensing Telescope Network (KMTNet) microlensing survey. develop optimized KMTNet AnomalyFinder algorithm and apply it to fields. find a total 13 homogeneously selected planets analysis three events, KMT-2019-BLG-(1042,1552,2974). The planet–host mass ratios, q, for events are 6.34 × 10−4, 4.89 10−3, 6.18 respectively. A Bayesian indicates all cold giant beyond snow line their host...
Abstract We present the analysis of seven microlensing planetary events with planet/host mass ratios q < 10 −4 : KMT-2017-BLG-1194, KMT-2017-BLG-0428, KMT-2019-BLG-1806, KMT-2017-BLG-1003, KMT-2019-BLG-1367, OGLE-2017-BLG-1806, and KMT-2016-BLG-1105. They were identified by applying Korea Microlensing Telescope Network (KMTNet) AnomalyFinder algorithm to 2016–2019 KMTNet events. A Bayesian indicates that all lens systems consist a cold super-Earth orbiting an M or K dwarf. Together 17...
Abstract We complete the analysis of planetary candidates found by KMT AnomalyFinder for 2017 prime fields that cover ∼13 deg 2 . report three unambiguous planets: OGLE-2017-BLG-0640, OGLE-2017-BLG-1275, and OGLE-2017-BLG-1237. The first two these were not previously identified, while last was published due to technical complications induced a nearby variable. further fourth anomalous event, recognized OGLE-2017-BLG-1777, is very likely be planetary, although its light curve requires...
Microlensing detections of cool planets are important for the construction an unbiased sample to estimate frequency beyond snow line, which is where giant thought form according core accretion theory planet formation. In this paper, we report discovery a detected from analysis light curve high-magnification microlensing event MOA 2010-BLG-477. The measured planet–star mass ratio q = (2.181 ± 0.004) × 10−3 and projected separation s 1.1228 0.0006 in units Einstein radius. angular radius...
Although many models have been proposed, the physical mechanisms responsible for formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass brown-dwarf function provide critical empirical diagnostics these mechanisms. We present discovery via gravitational microlensing two very low-mass, tight binary systems. These binaries directly precisely measured total system masses 0.025 Msun 0.034 Msun, projected separations 0.31 AU 0.19 AU, making them...
We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by Microlensing Observations in Astrophysics survey on 2010 March 18. This event was remarkable because source previously known to be photometrically variable. Analyzing pre-event light curve, we demonstrate that it is irregular variable over timescales >200 days. Its dereddened color, (V − I)S, 0, 1.221 ± 0.051 mag, and from our lens model derive a radius 14.7 1.3 R☉, suggesting red giant star. initially...
We present microlensing events in the 2015 Korea Microlensing Telescope Network (KMTNet) data and our procedure for identifying these events. In particular, candidates were detected with a novel "completed event" event-finder algorithm. The algorithm works by making linear fits to (t0,teff,u0) grid of point-lens models. This approach is rendered computationally efficient restricting u0 just two values (0 1), which we show quite adequate. implementation presented here specifically tailored...
We present the analysis of gravitational microlensing event OGLE-2013-BLG-0102. The light curve is characterized by a strong short-term anomaly superposed on smoothly varying lensing with moderate magnification $A_{\rm max}\sim 1.5$. It found that was produced binary lens mass ratio between components $q = 0.13$ and caused passage source trajectory over caustic located away from barycenter binary. From effects due to finite size parallactic motion Earth, physical parameters system are...
We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be first Spitzer microlensing planet in Galactic bulge/bar, an assignation that can confirmed by two epochs high-resolution imaging combined source-lens baseline object. The planet's mass M_p= 13.4+-0.9 M_J places it right at deuterium burning limit, i.e., conventional boundary between "planets" and "brown dwarfs". Its existence raises question whether such objects are really (formed within disks their hosts) or "failed...
We present microlensing planet OGLE-2017-BLG-0173Lb, with planet-host mass ratio either $q\simeq 2.5\times 10^{-5}$ or 6.5\times 10^{-5}$, the lowest among ever detected. The planetary perturbation is strongly detected, $\Delta\chi^2\sim 10,000$, because it arises from a bright (therefore, large) source passing over and enveloping caustic: so-called "Hollywood" event. factor $\sim 2.5$ offset in $q$ of previously unrecognized discrete degeneracy between Hollywood events which caustic fully...