Publications (45)
OGLE-2012-BLG-0563Lb: a Saturn-mass Planet around an M Dwarf with the Mass Constrained by Subaru AO imaging
A. Fukui, A. Gould, T. Sumi +58
We report the discovery of a microlensing exoplanet OGLE-2012-BLG-0563Lb with the planet-star mass ratio ~1 x 10^{-3}. Intensive photometric observations of a high-magnification mi…
MOA-2013-BLG-220Lb: Massive Planetary Companion to Galactic-Disk Host
J. C. Yee, C. Han, A. Gould +70
We report the discovery of MOA-2013-BLG-220Lb, which has a super-Jupiter mass ratio relative to its host. The proper motion, $μ=12.5\pm 1\, {\rm mas…
High-precision photometry by telescope defocussing. III. The transiting planetary system WASP-2
John Southworth, L. Mancini, S. Calchi Novati +23
We present high-precision photometry of three transits of the extrasolar planetary system WASP-2, obtained by defocussing the telescope, and achieving point-to-point scatters of be…
A Super-Jupiter orbiting a late-type star: A refined analysis of microlensing event OGLE-2012-BLG-0406
Y. Tsapras, J. -Y. Choi, R. A. Street +122
We present a detailed analysis of survey and follow-up observations of microlensing event OGLE-2012-BLG-0406 based on data obtained from 10 different observatories. Intensive cover…
Microlensig Binaries with Candidate Brown Dwarf Companions
I. -G. Shin, C. Han, A. Gould +152
Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation history. In this pa…
A Bayesian algorithm for model selection applied to caustic-crossing binary-lens microlensing events
N. Kains, P. Browne, K. Horne +2
We present a full Bayesian algorithm designed to perform automated searches of the parameter space of caustic-crossing binary-lens microlensing events. This builds on previous work…
Discovery and Mass Measurements of a Cold, 10-Earth Mass Planet and Its Host Star
Y. Muraki, C. Han, D. P. Bennett +125
We present the discovery and mass measurement of the cold, low-mass planet MOA-2009-BLG-266Lb, made with the gravitational microlensing method. This planet has a mass of m_p = 10.4…
MOA-2010-BLG-477Lb: constraining the mass of a microlensing planet from microlensing parallax, orbital motion and detection of blended light
E. Bachelet, I. -G. Shin, C. Han +138
Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant pla…
Characterizing Lenses and Lensed Stars of High-Magnification Single-lens Gravitational Microlensing Events With Lenses Passing Over Source Stars
J. -Y. Choi, I. -G. Shin, S. -Y. Park +148
We present the analysis of the light curves of 9 high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254…
I. Flux and color variations of the quadruply imaged quasar HE 0435-1223
D. Ricci, J. Poels, A. Elyiv +32
aims: We present VRi photometric observations of the quadruply imaged quasar HE 0435-1223, carried out with the Danish 1.54m telescope at the La Silla Observatory. Our aim was to m…
High-precision photometry by telescope defocussing. VI. WASP-24, WASP-25 and WASP-26
John Southworth, T. C. Hinse, M. Burgdorf +55
We present time-series photometric observations of thirteen transits in the planetary systems WASP-24, WASP-25 and WASP-26. All three systems have orbital obliquity measurements, W…
Candidate Gravitational Microlensing Events for Future Direct Lens Imaging
C. B. Henderson, H. Park, T. Sumi +76
The mass of the lenses giving rise to Galactic microlensing events can be constrained by measuring the relative lens-source proper motion and lens flux. The flux of the lens can be…
Microlensing Discovery of a Tight, Low Mass-ratio Planetary-mass Object around an Old, Field Brown Dwarf
C. Han, Y. K. Jung, A. Udalski +67
Observations of accretion disks around young brown dwarfs have led to the speculation that they may form planetary systems similar to normal stars. While there have been several de…
Microlensing Binaries Discovered through High-Magnification Channel
I. -G. Shin, J. -Y. Choi, S. -Y. Park +148
Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of 8 binary lensing ev…
Bayesian analysis of caustic-crossing microlensing events
A. Cassan, K. Horne, N. Kains +2
Aims: Caustic-crossing binary-lens microlensing events are important anomalous events because they are capable of detecting an extrasolar planet companion orbiting the lens star. F…
A Giant Planet beyond the Snow Line in Microlensing Event OGLE-2011-BLG-0251
N. Kains, R. Street, J. -Y. Choi +128
We present the analysis of the gravitational microlensing event OGLE-2011-BLG-0251. This anomalous event was observed by several survey and follow-up collaborations conducting micr…
A New Type of Ambiguity in the Planet and Binary Interpretations of Central Perturbations of High-Magnification Gravitational Microlensing Events
J. -Y. Choi, I. -G. Shin, C. Han +118
High-magnification microlensing events provide an important channel to detect planets. Perturbations near the peak of a high-magnification event can be produced either by a planet…
A much lower density for the transiting extrasolar planet WASP-7
John Southworth, M. Dominik, U. G. Jorgensen +29
We present the first high-precision photometry of the transiting extrasolar planetary system WASP-7, obtained using telescope defocussing techniques and reaching a scatter of 0.68…
High-precision photometry by telescope defocussing. V. WASP-15 and WASP-16
J. Southworth, L. Mancini, P. Browne +40
We present new photometric observations of WASP-15 and WASP-16, two transiting extrasolar planetary systems with measured orbital obliquities but without photometric follow-up sinc…
Transits and starspots in the WASP-6 planetary system
Jeremy Tregloan-Reed, John Southworth, M. Burgdorf +27
We present updates to \textsc{prism}, a photometric transit-starspot model, and \textsc{gemc}, a hybrid optimisation code combining MCMC and a genetic algorithm. We then present hi…
A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry
A. Arellano Ferro, D. M. Bramich, R. Figuera Jaimes +37
We report CCD and time-series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precisio…
MiNDSTEp differential photometry of the gravitationally lensed quasars WFI2033-4723 and HE0047-1756: Microlensing and a new time delay
E. Giannini, R. W. Schmidt, J. Wambsganà +52
We present V and R photometry of the gravitationally lensed quasars WFI2033-4723 and HE0047-1756. The data were taken by the MiNDSTEp collaboration with the 1.54 m Danish telescope…
The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation
K. B. W. Harpsøe, S. Hardis, T. C. Hinse +37
Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we inve…
Gravitational Binary-lens Events with Prominent Effects of Lens Orbital Motion
H. Park, A. Udalski, C. Han +58
Gravitational microlensing events produced by lenses composed of binary masses are important because they provide a major channel to determine physical parameters of lenses. In thi…
OGLE-2009-BLG-092/MOA-2009-BLG-137: A Dramatic Repeating Event With the Second Perturbation Predicted by Real-Time Analysis
Y. -H. Ryu, C. Han, K. -H. Hwang +105
We report the result of the analysis of a dramatic repeating gravitational microlensing event OGLE-2009-BLG-092/MOA-2009-BLG-137, for which the light curve is characterized by two…
EMCCD photometry reveals two new variable stars in the crowded central region of the globular cluster NGC 6981
Jesper Skottfelt, D. M. Bramich, R. Figuera Jaimes +33
Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the Electron Multiplying CCD (E…
Binary microlensing event OGLE-2009-BLG-020 gives a verifiable mass, distance and orbit predictions
J. Skowron, A. Udalski, A. Gould +99
We present the first example of binary microlensing for which the parameter measurements can be verified (or contradicted) by future Doppler observations. This test is made possibl…
Faint source star planetary microlensing: the discovery of the cold gas giant planet OGLE-2014-BLG-0676Lb
N. J. Rattenbury, D. P. Bennett, T. Sumi +85
We report the discovery of a planet --- OGLE-2014-BLG-0676Lb --- via gravitational microlensing. Observations for the lensing event were made by the MOA, OGLE, Wise, RoboNET/LCOGT,…
MOA-2010-BLG-523: "Failed Planet" = RS CVn Star
A. Gould, J. C. Yee, I. A. Bond +116
The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing lightcurve near the peak of an Amax ~ 265 high-magnification microlensing e…
Physical properties, transmission and emission spectra of the WASP-19 planetary system from multi-colour photometry
L. Mancini, S. Ciceri, G. Chen +43
We present new ground-based, multi-colour, broad-band photometric measurements of the physical parameters, transmission and emission spectra of the transiting extrasolar planet WAS…
Physical properties of the planetary systems WASP-45 and WASP-46 from simultaneous multi-band photometry
S. Ciceri, L. Mancini, J. Southworth +45
Accurate measurements of the physical characteristics of a large number of exoplanets are useful to strongly constrain theoretical models of planet formation and evolution, which l…
MOA-2010-BLG-328Lb: a sub-Neptune orbiting very late M dwarf ?
K. Furusawa, A. Udalski, T. Sumi +119
We analyze the planetary microlensing event MOA-2010-BLG-328. The best fit yields host and planetary masses of Mh = 0.11+/-0.01 M_{sun} and Mp = 9.2+/-2.2M_Earth, corresponding to…
Interpretation of a Short-Term Anomaly in the Gravitational Microlensing Event MOA-2012-BLG-486
K. -H. Hwang, J. -Y. Choi, I. A. Bond +78
A planetary microlensing signal is generally characterized by a short-term perturbation to the standard single lensing light curve. A subset of binary-source events can produce per…
Physical properties of the 0.94-day period transiting planetary system WASP-18
John Southworth, T. C. Hinse, M. Dominik +24
We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of tele…
Microlensing Discovery of a Population of Very Tight, Very Low-mass Binary Brown Dwarfs
J. -Y. Choi, C. Han, A. Udalski +121
Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minim…
Square Kilometre Array Science Data Challenge 3a: foreground removal for an EoR experiment
A. Bonaldi, P. Hartley, R. Braun +179
We present and analyse the results of the Science data challenge 3a (SDC3a, https://sdc3.skao.int/challenges/foregrounds), an EoR foreground-removal community-wide exercise organis…
OGLE-2011-BLG-0265Lb: a Jovian Microlensing Planet Orbiting an M Dwarf
J. Skowron, I. -G. Shin, A. Udalski +121
We report the discovery of a Jupiter-mass planet orbiting an M-dwarf star that gave rise to the microlensing event OGLE-2011-BLG-0265. Such a system is very rare among known planet…
A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge
D. P. Bennett, V. Batista, I. A. Bond +90
We present the first microlensing candidate for a free-floating exoplanet-exomoon system, MOA-2011-BLG-262, with a primary lens mass of M_host ~ 4 Jupiter masses hosting a sub-Eart…
Flux and color variations of the doubly imaged quasar UM673
D. Ricci, A. Elyiv, F. Finet +42
With the aim of characterizing the flux and color variations of the multiple components of the gravitationally lensed quasar UM673 as a function of time, we have performed multi-ep…
MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detection
J. C. Yee, L. -W. Hung, I. A. Bond +123
We analyze MOA-2010-BLG-311, a high magnification (A_max>600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit th…
A sub-Saturn Mass Planet, MOA-2009-BLG-319Lb
N. Miyake, T. Sumi, Subo Dong +119
We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K or M-dwarf star in the inner Galactic disk or Galactic bulge. The h…
Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry
N. Kains, D. M. Bramich, A. Arellano Ferro +47
We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars i…
Characterizing Low-Mass Binaries From Observation of Long Time-scale Caustic-crossing Gravitational Microlensing Events
I. -G. Shin, C. Han, J. -Y. Choi +119
Despite astrophysical importance of binary star systems, detections are limited to those located in small ranges of separations, distances, and masses and thus it is necessary to u…
MOA-2010-BLG-073L: An M-Dwarf with a Substellar Companion at the Planet/Brown Dwarf Boundary
R. A. Street, J. -Y. Choi, Y. Tsapras +129
We present an analysis of the anomalous microlensing event, MOA-2010-BLG-073, announced by the Microlensing Observations in Astrophysics survey on 2010-03-18. This event was remark…
A Census of Variability in Globular Cluster M68 (NGC 4590)
N. Kains, A. Arellano Ferro, R. Figuera Jaimes +32
We analyse 20 nights of CCD observations in the V and I bands of the globular cluster M68 (NGC 4590), using these to detect variable objects. We also obtained electron-multiplying…