Publications (106)
OGLE 2008--BLG--290: An accurate measurement of the limb darkening of a Galactic Bulge K Giant spatially resolved by microlensing
P. Fouque, D. Heyrovsky, S. Dong +115
Gravitational microlensing is not only a successful tool for discovering distant exoplanets, but it also enables characterization of the lens and source stars involved in the lensi…
Large-scale changes of the cloud coverage in the Indi Ba,Bb system
J. A. Hitchcock, Ch. Helling, A. Scholz +22
We present the results of 14 nights of \textit{I}-band photometric monitoring of the nearby brown dwarf binary, Indi Ba,Bb. Observations were acquired over 2 months, and total…
Search for hidden turbulent gas through interstellar scintillation
M. Moniez, R. Ansari, F. Habibi +1
Stars twinkle because their light propagates through the atmosphere. The same phenomenon is expected when the light of remote stars crosses a Galactic - disk or halo - refractive m…
Searching for Galactic hidden gas through interstellar scintillation: Results from a test with the NTT-SOFI detector
F. Habibi, Marc Moniez, R. Ansari +1
Aims: Stars twinkle because their light propagates through the atmosphere. The same phenomenon is expected at a longer time scale when the light of remote stars crosses an interste…
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…
Resolving Microlensing Events with Triggered VLBI
M. Karami, A. E. Broderick, S. Rahvar +1
Microlensing events provide a unique capacity to study the stellar remnant population of the Galaxy. Optical microlensing suffers from a near complete degeneracy between the mass,…
Long-term monitoring of WASP-19 b: Signs of apsidal precession and molecular signatures
A. R. Rajkumar, A. Bayo, P. Peng +30
With more than 6000 exoplanets discovered so far, about 12 percent are hot Jupiters. Their large sizes and short orbital periods make them valuable targets for studying planetary f…
Physical properties and transmission spectrum of the WASP-80 planetary system from multi-colour photometry
L. Mancini, J. Southworth, S. Ciceri +29
WASP-80 is one of only two systems known to contain a hot Jupiter which transits its M-dwarf host star. We present eight light curves of one transit event, obtained simultaneously…
Many new variable stars discovered in the core of the globular cluster NGC 6715 (M54) with EMCCD observations
R. Figuera Jaimes, D. M. Bramich, N. Kains +38
We show the benefits of using Electron-Multiplying CCDs and the shift-and-add technique as a tool to minimise the effects of the atmospheric turbulence such as blending between sta…
The first observed stellar occultations by the irregular satellite (Saturn IX) Phoebe and improved rotational period
A. R. Gomes-Júnior, M. Assafin, F. Braga-Ribas +24
We report six stellar occultations by (Saturn IX) Phoebe, an irregular satellite of Saturn, obtained between mid-2017 and mid-2019. The 2017 July 06 event is the first stellar occu…
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…
OGLE-2015-BLG-0479LA,B: Binary Gravitational Microlens Characterized by Simultaneous Ground-based and Space-based Observation
C. Han, A. Udalski, A. Gould +60
We present a combined analysis of the observations of the gravitational microlensing event OGLE-2015-BLG-0479 taken both from the ground and by the {\it Spitzer Space Telescope}. T…
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…
High-precision photometry by telescope defocussing. II. The transiting planetary system WASP-4
John Southworth, T. C. Hinse, M. J. Burgdorf +18
We present and analyse light curves of four transits of the Southern hemisphere extrasolar planetary system WASP-4, obtained with a telescope defocussed so the radius of each point…
Digging deeper into the dense Galactic globular cluster Terzan 5 with Electron-Multiplying CCDs. Variable star detection and new discoveries
R. Figuera Jaimes, M. Catelan, K. Horne +20
Context. High frame-rate imaging was employed to mitigate the effects of atmospheric turbulence (seeing) in observations of globular cluster Terzan 5. Aims. High-precision time-ser…
OGLE-2013-BLG-0911Lb: A Secondary on the Brown-Dwarf Planet Boundary around an M-dwarf
Shota Miyazaki, Takahiro Sumi, David P. Bennett +92
We present the analysis of the binary-lens microlensing event OGLE-2013-BLG-0911. The best-fit solutions indicate the binary mass ratio of q~0.03 which differs from that reported i…
The EROS2 search for microlensing events towards the spiral arms: the complete seven season results
Y. R. Rahal, C. Afonso, J. -N. Albert +36
The EROS-2 project has been designed to search for microlensing events towards any dense stellar field. The densest parts of the Galactic spiral arms have been monitored to maximiz…
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…
Measuring Limb Darkening of Stars in high magnification Microlensing Events by the Finite Element Method
L. Golchin, S. Rahvar
The finite-size effect in gravitational microlensing provides a possibility to measure the limb darkening of distant stars. We use the Finite Element Method (FEM) as an inversion t…
Spherical Collapse in Modified Newtonian Dynamics (MOND)
M. Malekjani, S. Rahvar, H. Haghi
Modeling the structure formation in the universe, we extend the spherical collapse model in the context of MOND starting with the linear Newtonian structure formation followed by t…
High-precision photometry by telescope defocussing. VII. The ultra-short period planet WASP-103
John Southworth, L. Mancini, S. Ciceri +25
We present 17 transit light curves of the ultra-short period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to estab…
Campaign 9 of the Mission: Observational Parameters, Scientific Drivers, and Community Involvement for a Simultaneous Space- and Ground-based Microlensing Survey
Calen B. Henderson, RadosÅaw Poleski, Matthew Penny +118
's Campaign 9 (C9) will conduct a 3.7 deg survey toward the Galactic bulge from 7/April through 1/July of 2016 that will leverage the spatial separation between…
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…
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…
High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). I. Lucky imaging observations of 101 systems in the southern hemisphere
D. F. Evans, J. Southworth, P. F. L. Maxted +33
(abridged) Context. Wide binaries are a potential pathway for the formation of hot Jupiters. The binary fraction among host stars is an important discriminator between competing fo…
Exploring the crowded central region of 10 Galactic globular clusters using EMCCDs. Variable star searches and new discoveries
R. Figuera Jaimes, D. M. Bramich, J. Skottfelt +31
Obtain time-series photometry of the very crowded central regions of Galactic globular clusters with better angular resolution than previously achieved with conventional CCDs on gr…
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…
Study of a Strategy for Parallax Microlensing Detection Towards the Magellanic Clouds
S. Rahvar, M. Moniez, R. Ansari +1
In this article, we have investigated the possibility to distinguish between different galactic models through the microlensing parallax studies. We show that a systematic search f…
OGLE-2017-BLG-1434Lb: Eighth q < 1 * 10^-4 Mass-Ratio Microlens Planet Confirms Turnover in Planet Mass-Ratio Function
A. Udalski, Y. -H. Ryu, S. Sajadian +55
We report the discovery of a cold Super-Earth planet (m_p=4.4 +/- 0.5 M_Earth) orbiting a low-mass (M=0.23 +/- 0.03 M_Sun) M dwarf at projected separation a_perp = 1.18 +/- 0.10 AU…
The Effect of Uncertainty Principle on the Thermodynamics of Early Universe
S. Rahvar, M. Sadegh Movahed, M Saadat
We discuss the concept of measurement in cosmology from the relativistic and quantum mechanical points of view. The uncertainty principle within the particle horizon, excludes the…
OGLE-2018-BLG-0022: A Nearby M-dwarf Binary
R. A. Street, E. Bachelet, Y. Tsapras +28
We report observations of the binary microlensing event OGLE-2018-BLG-0022, provided by the ROME/REA Survey, which indicate that the lens is a low-mass binary star consisting of M3…
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…
Physical properties of the WASP-67 planetary system from multi-colour photometry
L. Mancini, J. Southworth, S. Ciceri +29
The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. The lack of the second and third contact point in this planetary syste…
Red noise versus planetary interpretations in the microlensing event OGLE-2013-BLG-446
E. Bachelet, D. M. Bramich, C. Han +98
For all exoplanet candidates, the reliability of a claimed detection needs to be assessed through a careful study of systematic errors in the data to minimize the false positives r…
OGLE-2015-BLG-1609Lb: Sub-jovian planet orbiting a low-mass stellar or brown dwarf host
M. J. Mróz, R. Poleski, A. Udalski +70
We present a comprehensive analysis of a planetary microlensing event OGLE-2015-BLG-1609. The planetary anomaly was detected by two survey telescopes, OGLE and MOA. Each of these s…
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…
OGLE-2016-BLG-1190Lb: First Spitzer Bulge Planet Lies Near the Planet/Brown-Dwarf Boundary
Y. -H. Ryu, J. C. Yee, A. Udalski +106
We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/bar, an assignation that can be confirmed by two…
The MOG Weak Field approximation II. Observational test of Chandra X-ray Clusters
J. W. Moffat, S. Rahvar
We apply the weak field approximation limit of the covariant Scalar-Tensor-Vector Gravity (STVG) theory, so-called MOdified gravity (MOG), to the dynamics of clusters of galaxies b…
A search for transit timing variations in the transiting hot Jupiter systems HIP 65, NGTS-6, NGTS-10 and WASP-173
A. W. Griffiths, J. Southworth, L. Alegre +30
Hot Jupiters are Jupiter-mass planets with orbital periods of less than ten days. Their short orbital separations make tidal dissipation within the stellar host especially efficien…
Pathway to the Galactic Distribution of Planets: Combined Spitzer and Ground-Based Microlens Parallax Measurements of 21 Single-Lens Events
S. Calchi Novati, A. Gould, A. Udalski +82
We present microlens parallax measurements for 21 (apparently) isolated lenses observed toward the Galactic bulge that were imaged simultaneously from Earth and Spitzer, which was…
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,…
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…
OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?
V. Bozza, M. Dominik, N. J. Rattenbury +103
The microlensing event OGLE-2008-BLG-510 is characterised by an evident asymmetric shape of the peak, promptly detected by the ARTEMiS system in real time. The skewness of the ligh…
The Orbit of WASP-4 b is in Decay
Ã. BaÅtürk, A. C. Kutluay, A. Barker +25
WASP-4 b is a hot Jupiter exhibiting a decreasing orbital period, prompting investigations into potential mechanisms driving its evolution. We analyzed 173 transit light curves, in…
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…
Applying MOG to lensing: Einstein rings, Abell 520 and the Bullet Cluster
J. W. Moffat, S. Rahvar, V. T. Toth
We investigate gravitational lensing in the context of the MOG modified theory of gravity. Using a formulation of the theory with no adjustable or fitted parameters, we present the…
Rotation periods and astrometric motions of the Luhman 16AB brown dwarfs by high-resolution lucky-imaging monitoring
L. Mancini, P. Giacobbe, S. P. Littlefair +33
Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres. The brown-dwarf binary sy…
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…
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…
Inferring statistics of planet populations by means of automated microlensing searches
M. Dominik, U. G. Jorgensen, K. Horne +17
(abridged) The study of other worlds is key to understanding our own, and not only provides clues to the origin of our civilization, but also looks into its future. Rather than in…
Propagation of Electromagnetic Waves in MOG: Gravitational Lensing
S. Rahvar, J. W. Moffat
We investigate the solution of Maxwell's equations in curved spacetime within the framework of Modified Gravity (MOG). We show that besides the null-geodesic treatment of photons i…
Primordial black hole detection through diffractive microlensing
T. Naderi, A. Mehrabi, S. Rahvar
Recent observations of gravitational waves motivate investigations for the existence of Primordial Black Holes (PBHs). We propose the observation of gravitational microlensing of d…
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…
An analysis of binary microlensing event OGLE-2015-BLG-0060
Y. Tsapras, A. Cassan, C. Ranc +83
We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous par…
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…
OGLE-2018-BLG-1185b : A Low-Mass Microlensing Planet Orbiting a Low-Mass Dwarf
Iona Kondo, Jennifer C. Yee, David P. Bennett +94
We report the analysis of planetary microlensing event OGLE-2018-BLG-1185, which was observed by a large number of ground-based telescopes and by the Space Telescope. The…
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…
Star-spot activity, orbital obliquity, transmission spectrum, physical properties, and TTVs of the HATS-2 planetary system
F. Biagiotti, L. Mancini, J. Southworth +23
Our aim in this paper is to refine the orbital and physical parameters of the HATS-2 planetary system and study transit timing variations and atmospheric composition thanks to tran…
A template-free approach for waveform extraction of gravitational wave events
A. Akhshi, H. Alimohammadi, S. Baghram +3
We develop a general data-driven and template-free method for the extraction of event waveforms in the presence of background noise. Recent gravitational-wave observations provide…
High-precision photometry by telescope defocussing. VIII. WASP-22, WASP-41, WASP-42 and WASP-55
John Southworth, J. Tregloan-Reed, M. I. Andersen +47
We present 13 high-precision and four additional light curves of four bright southern-hemisphere transiting planetary systems: WASP-22, WASP-41, WASP-42 and WASP-55. In the cases o…
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…
VLT, GROND and Danish Telescope observations of transits in the TRAPPIST-1 system
John Southworth, L. Mancini, M. Dominik +14
TRAPPIST-1 is an ultra-cool dwarf that hosts seven known transiting planets. We present photometry of the system obtained using three telescopes at ESO La Silla (the Danish 1.54-m…
OGLE-2017-BLG-0406: Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk
Yuki Hirao, David P. Bennett, Yoon-Hyun Ryu +93
We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the satellite in a solar…
The MOG weak field approximation and observational test of galaxy rotation curves
J. W. Moffat, S. Rahvar
As an alternative to dark matter models, MOdified Gravity (MOG) theory can compensate for dark matter by a covariant modification of Einstein gravity. The theory introduces two add…
Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
A. Herald, A. Udalski, V. Bozza +89
Context. Brown dwarfs are poorly understood transition objects between stars and planets, with several competing mechanisms having been proposed for their formation. Mass measureme…
Spitzer Parallax of OGLE-2015-BLG-0966: A Cold Neptune in the Galactic Disk
R. A. Street, A. Udalski, S. Calchi Novati +106
We report the detection of a Cold Neptune m_planet=21+/-2MEarth orbiting a 0.38MSol M dwarf lying 2.5-3.3 kpc toward the Galactic center as part of a campaign combining ground-base…
A search for transit timing variations in the HATS-18 planetary system
John Southworth, A. J. Barker, T. C. Hinse +23
HATS-18b is a transiting planet with a large mass and a short orbital period, and is one of the best candidates for the detection of orbital decay induced by tidal effects. We pres…
Transit timing variations in the WASP-4 planetary system
John Southworth, M. Dominik, U. G. Jorgensen +25
Transits in the planetary system WASP-4 were recently found to occur 80s earlier than expected in observations from the TESS satellite. We present 22 new times of mid-transit that…
Observational Tests of Nonlocal Gravity: Galaxy Rotation Curves and Clusters of Galaxies
S. Rahvar, B. Mashhoon
A classical nonlocal generalization of Einstein's theory of gravitation has recently been developed via the introduction of a scalar causal "constitutive" kernel that must ultimate…
Spitzer Observations of OGLE-2015-BLG-1212 Reveal a New Path to Breaking Strong Microlens Degeneracies
V. Bozza, Y. Shvartzvald, A. Udalski +98
Spitzer microlensing parallax observations of OGLE-2015-BLG-1212 decisively breaks a degeneracy between planetary and binary solutions that is somewhat ambiguous when only ground-b…
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…
Searching for variable stars in the cores of five metal rich globular clusters using EMCCD observations
Jesper Skottfelt, D. M. Bramich, R. Figuera Jaimes +31
In this paper, we present the analysis of time-series observations from 2013 and 2014 of five metal rich ([Fe/H] -1) globular clusters: NGC~6388, NGC~6441, NGC~6528, NGC~6638,…
First simultaneous microlensing observations by two space telescopes: & reveal a brown dwarf in event OGLE-2015-BLG-1319
Y. Shvartzvald, Z. Li, A. Udalski +90
Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically…
Possibility of primordial black holes as the source of gravitational wave events in the advanced LIGO detector
E. Khalouei, H. Ghodsi, S. Rahvar +1
The analysis of gravitational Wave (GW) data from advanced LIGO provides the mass of each companion of binary black holes as the source of GWs. The mass of events corresponding to…
High-precision photometry by telescope defocussing. I. The transiting planetary system WASP-5
John Southworth, T. C. Hinse, U. G. Joergensen +20
We present high-precision photometry of two transit events of the extrasolar planetary system WASP-5, obtained with the Danish 1.54m telescope at ESO La Silla. In order to minimise…
Larger and faster: revised properties and a shorter orbital period for the WASP-57 planetary system from a pro-am collaboration
John Southworth, L. Mancini, J. Tregloan-Reed +36
Transits in the WASP-57 planetary system have been found to occur half an hour earlier than expected. We present ten transit light curves from amateur telescopes, on which this dis…
Stellar occultations enable milliarcsecond astrometry for Trans-Neptunian objects and Centaurs
F. L. Rommel, F. Braga-Ribas, J. Desmars +66
Trans-Neptunian objects (TNOs) and Centaurs are remnants of our planetary system formation, and their physical properties have invaluable information for evolutionary theories. Ste…
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…
Planetary microlensing signals from the orbital motion of the source star around the common barycentre
S. Rahvar, M. Dominik
With several detections, the technique of gravitational microlensing has proven useful for studying planets that orbit stars at Galactic distances, and it can even be applied to de…
Two Component Baryonic-Dark Matter Structure Formation in Top-Hat Model
M. Malekjani, S. Rahvar, D. M. Z. Jassur
In this work we extend simple top-hat model of structure formation to the two-component system made of baryonic and dark matter. We use Harrison-Zeldovich spectrum as the initial c…
Six Outbursts of Comet 46P/Wirtanen
Michael S. P. Kelley, Tony L. Farnham, Jian-Yang Li +32
Cometary activity is a manifestation of sublimation-driven processes at the surface of nuclei. However, cometary outbursts may arise from other processes that are not necessarily d…
Search for Turbulent Gas through Interstellar Scintillation
Marc Moniez, R. Ansari, F. Habibi +1
Stars twinkle because their light propagates through the atmosphere. The same phenomenon is expected when the light of remote stars crosses a Galactic - disk or halo - refractive m…
Testing MOG, Non-Local Gravity and MOND with rotation curves of dwarf galaxies
M. H. Zhoolideh Haghighi, S. Rahvar
Modified Gravity (MOG) and Non-Local Gravity (NLG) are two alternative theories to General Relativity. They are able to explain the rotation curves of spiral galaxies and clusters…
Mass Measurements of Isolated Objects from Space-based Microlensing
Wei Zhu, S. Calchi Novati, A. Gould +78
We report on the mass and distance measurements of two single-lens events from the 2015 \emph{Spitzer} microlensing campaign. With both finite-source effect and microlens parallax…
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…
Physical properties and transmission spectrum of the WASP-74 planetary system from multi-band photometry
L. Mancini, J. Southworth, P. Molliere +32
We present broad-band photometry of eleven planetary transits of the hot Jupiter WASP-74b, using three medium-class telescopes and employing the telescope-defocussing technique. Mo…
High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016
D. F. Evans, J. Southworth, B. Smalley +33
The formation and dynamical history of hot Jupiters is currently debated, with wide stellar binaries having been suggested as a potential formation pathway. Additionally, contamina…
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…
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…
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
P. Rota, V. Bozza, M. Hundertmark +22
Context. Gravitational microlensing is a method that is used to discover planet-hosting systems at distances of several kiloparsec in the Galactic disk and bulge. We present the an…
Orbital alignment and starspot properties in the WASP-52 planetary system
L. Mancini, J. Southworth, G. Raia +27
We report 13 high-precision light curves of eight transits of the exoplanet WASP-52b, obtained by using four medium-class telescopes, through different filters, and adopting the de…