Publications (177)
Gravitational Lensing of stars in the central arcsecond of our Galaxy
V. Bozza, L. Mancini
In the neighborhood of Sgr A*, several stars (S2, S12, S14, S1, S8, S13) enjoy an accurate determination of their orbital parameters. General Relativity predicts that the central b…
A Venus-Mass Planet Orbiting a Brown Dwarf: Missing Link between Planets and Moons
A. Udalski, Y. K. Jung, C. Han +20
The co-planarity of solar-system planets led Kant to suggest that they formed from an accretion disk, and the discovery of hundreds of such disks around young stars as well as hund…
Electromagnetic probes of primordial black holes as dark matter
Y. Ali-Haimoud, S. Clesse, J. Garcia-Bellido +91
The LIGO discoveries have rekindled suggestions that primordial black holes (BHs) may constitute part to all of the dark matter (DM) in the Universe. Such suggestions came from 1)…
Ground-based parallax confirmed by Spitzer: binary microlensing event MOA-2015-BLG-020
Tianshu Wang, Wei Zhu, Shude Mao +83
We present the analysis of the binary gravitational microlensing event MOA-2015-BLG-020. The event has a fairly long timescale (about 63 days) and thus the light curve deviates sig…
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…
VBBinaryLensing: a public package for microlensing light curve computation
V. Bozza, E. Bachelet, F. BartoliÄ +3
The computation of microlensing light curves represents a bottleneck for the modeling of planetary events, making broad searches in the vast parameter space of microlensing extreme…
Microlensing with advanced contour integration algorithm: Green's theorem to third order, error control, optimal sampling and limb darkening
V. Bozza
Microlensing light curves are typically computed either by ray-shooting maps or by contour integration via Green's theorem. We present an improved version of the second method that…
Spitzer Microlensing Parallax for OGLE-2016-BLG-1067: a sub-Jupiter Orbiting an M-dwarf in the Disk
S. Calchi Novati, D. Suzuki, A. Udalski +65
We report the discovery of a sub-Jupiter mass planet orbiting beyond the snow line of an M-dwarf most likely in the Galactic disk as part of the joint Spitzer and ground-based moni…
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…
Strong deflection limit of black hole gravitational lensing with arbitrary source distances
V. Bozza, G. Scarpetta
The gravitational field of supermassive black holes is able to strongly bend light rays emitted by nearby sources. When the deflection angle exceeds , gravitational lensing can…
Microlensing of strongly interacting binary systems
V. Bozza, L. Mancini
Many binary systems are in a state of strong interaction, where mass exchanges, accretion disks, common envelopes provide circumstellar matter which can have significant effects in…
Lens mass estimate in the Galactic disk extreme parallax microlensing event Gaia19dke
M. MaskoliÅ«nas, Å. Wyrzykowski, K. Howil +74
We present the results of our analysis of Gaia19dke, an extraordinary microlensing event in the Cygnus constellation that was first spotted by the {\gaia} satellite. This event fea…
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…
Gaia20fnr: A binary-lens microlensing event with full orbital motion revealed by four space telescopes
M. Wicker, Å. Wyrzykowski, M. Hundertmark +49
The microlensing event Gaia20fnr is a long-duration, non-caustic-crossing binary-lens event at high Galactic latitude. Triggered by a photometric rise detected by the Gaia space mi…
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…
Constraints on pre-big bang parameter space from CMBR anisotropies
V. Bozza, M. Gasperini, M. Giovannini +1
The so-called curvaton mechanism --a way to convert isocurvature perturbations into adiabatic ones-- is investigated both analytically and numerically in a pre-big bang scenario wh…
Analytic Kerr black hole lensing for equatorial observers in the strong deflection limit
V. Bozza, F. De Luca, G. Scarpetta +1
In this paper we present an analytical treatment of gravitational lensing by Kerr black holes in the limit of very large deflection angles, restricting to observers in the equatori…
Kojima-1Lb Is a Mildly Cold Neptune around the Brightest Microlensing Host Star
A. Fukui, D. Suzuki, N. Koshimoto +56
We report the analysis of additional multiband photometry and spectroscopy and new adaptive optics (AO) imaging of the nearby planetary microlensing event TCP J05074264+2447555 (Ko…
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…
Orientation of orbital planes of planetary systems detected in microlensing campaigns
V. Bozza, P. Rota
Galactic microlensing has the capability to determine the position angle of the detected planets in a sky reference frame. By a broad enough statistics, it is possible to investiga…
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 by Compact Objects associated to Gas Clouds
V. Bozza, Ph. Jetzer, L. Mancini +1
We investigate gravitational microlensing of point-like lenses surrounded by diffuse gas clouds. Besides gravitational bending, one must also consider refraction and absorption phe…
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 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…
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…
Historic microlensing events in the euclid Galactic Bulge Survey
V. Bozza, L. Salmeri, P. Rota +47
Microlensing campaigns have a long history of observations covering the Galactic bulge, where thousands of detections have been obtained, including many exoplanetary systems. The E…
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…
Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-Velocity Characterization
Zexuan Wu, Subo Dong, Tuan Yi +50
We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensin…
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…
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…
OGLE-2014-BLG-0257L: A Microlensing Brown Dwarf Orbiting a Low-mass M Dwarf
C. Han, Y. K. Jung, A. Udalski +10
In this paper, we report the discovery of a binary composed of a brown dwarf and a low-mass M dwarf from the observation of the microlensing event OGLE-2014-BLG-0257. Resolution of…
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…
Cosmological Perturbations from a New-Physics Hypersurface
V. Bozza, M. Giovannini, G. Veneziano
Within a broad class of inflationary models we critically analyze the way initial quantum fluctuations on a new-physics hypersurface (NPH) affect standard predictions for large-sca…
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 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…
Quasi-Equatorial Gravitational Lensing by Spinning Black Holes in the Strong Field Limit
V. Bozza
Spherically symmetric black holes produce, by strong field lensing, two infinite series of relativistic images, formed by light rays winding around the black hole at distances comp…
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…
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…
Gravitational lensing in the strong field limit
V. Bozza
We provide an analytic method to discriminate among different types of black holes on the ground of their strong field gravitational lensing properties. We expand the deflection an…
Assisting pre-big bang phenomenology through short-lived axions
V. Bozza, M. Gasperini, M. Giovannini +1
We present the results of a detailed study of how isocurvature axion fluctuations are converted into adiabatic metric perturbations through axion decay, and discuss the constraints…
ROME/REA: A gravitational microlensing search for exo-planets beyond the snow-line on a global network of robotic telescopes
Yiannis Tsapras, R. A. Street, M. Hundertmark +10
Planet population synthesis models predict an abundance of planets with semi-major axes between 1-10 au, yet they lie at the edge of the detection limits of most planet finding tec…
Gravitational Lensing by Black Holes: a comprehensive treatment and the case of the star S2
V. Bozza, L. Mancini
Light rays passing very close to a black hole may experience very strong deviations. Two geometries were separately considered in the recent literature: a source behind the black h…
MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary
E. Bachelet, Y. Tsapras, Andrew Gould +68
We report on the observations, analysis and interpretation of the microlensing event MOA-2019- BLG-008. The observed anomaly in the photometric light curve is best described throug…
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…
MOA-2020-BLG-208Lb: Cool Sub-Saturn Planet Within Predicted Desert
Greg Olmschenk, David P. Bennett, Ian A. Bond +74
We analyze the MOA-2020-BLG-208 gravitational microlensing event and present the discovery and characterization of a new planet, MOA-2020-BLG-208Lb, with an estimated sub-Saturn ma…
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…
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…
Optical caustics of Kerr spacetime: the full structure
V. Bozza
We present an exhaustive numerical investigation of the optical caustics in gravitational lensing by a spinning black hole for an observer at infinity. Besides the primary caustic,…
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…
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…
Lens parameters for Gaia18cbf -- a long gravitational microlensing event in the Galactic plane
Katarzyna KruszyÅska, Å. Wyrzykowski, K. A. Rybicki +29
Context: The timescale of a microlensing event scales as a square root of a lens mass. Therefore, long-lasting events are important candidates for massive lenses, including black h…
Decoding a black hole metric from the interferometric pattern of the relativistic images of a compact source
F. Aratore, V. Bozza
Photons emitted by light sources in the neighbourhood of a black hole can wind several times around it before fleeing towards the observer. For spherically symmetric black holes, t…
Microlensing by gas filaments
V. Bozza, L. Mancini
Gas in the interstellar matter is generally organized in filamentary structures, which may be also relevant for a complementary explanation of the dark matter in the Galactic halo.…
Constraining Lens Masses in Moderately to Highly Magnified Microlensing Events from Gaia
U. Pylypenko, Å. Wyrzykowski, P. J. MikoÅajczyk +57
Microlensing events provide a unique way to detect and measure the masses of isolated, non-luminous objects, particularly dark stellar remnants. Under certain conditions, it is pos…
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…
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…
OGLE-2017-BLG-0039: Microlensing Event with Light from the Lens Identified from Mass Measurement
C. Han, Y. K. Jung, A. Udalski +58
We present the analysis of the caustic-crossing binary microlensing event OGLE-2017-BLG-0039. Thanks to the very long duration of the event, with an event time scale $t_{\rm E}\sim…
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…
Gravitational lensing by the supermassive black hole in the center of M31
V. Bozza, S. Calchi Novati, L. Mancini
We examine the possibility of observing gravitational lensing in the weak deflection regime by the supermassive black hole in the center of the galaxy M31. This black hole is signi…
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…
Candidate microlensing events from M31 observations with the Loiano telescope
S. Calchi Novati, V. Bozza, F. De Paolis +9
Microlensing observations towards M31 are a powerful tool for the study of the dark matter population in the form of MACHOs both in the Galaxy and the M31 halos, a still unresolved…
OGLE-2017-BLG-0329L: A Microlensing Binary Characterized with Dramatically Enhanced Precision Using Data from Space-based Observations
C. Han, S. Calchi Novati, A. Udalski +54
Mass measurements of gravitational microlenses require one to determine the microlens parallax $\pie$, but precise $\pie$ measurement, in many cases, is hampered due to the subtlet…
OGLE-2014-BLG-1112LB: A Microlensing Brown Dwarf Detected Through the Channel of a Gravitational Binary-Lens Event
C. Han, A. Udalski, V. Bozza +15
Due to the nature depending on only the gravitational field, microlensing, in principle, provides an important tool to detect faint and even dark brown dwarfs. However, the number…
Quantum Violations of the Equivalence Principle in a Modified Schwarzschild Geometry. Neutrino Oscillations
V. Bozza, G. Lambiase, G. Papini +1
Neutrino flavour oscillations are analyzed in a model in which particles experience an effective Schwarzschild geometry modified by maximal acceleration corrections. These imply a…
VBMicroLensing: three algorithms for multiple lensing with contour integration
V. Bozza, V. Saggese, G. Covone +2
Modeling of microlensing events poses computational challenges for the resolution of the lens equation and the high dimensionality of the parameter space. In particular, numerical…
M31 pixel lensing event OAB-N2: a study of the lens proper motion
S. Calchi Novati, M. Dall'Ora, A. Gould +12
We present an updated analysis of the M31 pixel lensing candidate event OAB-N2 previously reported in Calchi Novati et al. (2009). Here we take advantage of new data both astrometr…
Spitzer Microlensing Program as a Probe for Globular Cluster Planets. Analysis of OGLE-2015-BLG-0448
RadosÅaw Poleski, Wei Zhu, Grant W. Christie +83
The microlensing event OGLE-2015-BLG-0448 was observed by Spitzer and lay within the tidal radius of the globular cluster NGC 6558. The event had moderate magnification and was int…
Cosmological perturbations in bouncing cosmologies and the case of the Pre-Big Bang scenario
V. Bozza
The Pre-Big Bang cosmology inspired generations of cosmologists in attempts to cure the initial Big Bang singularity using a fundamental length scale as proposed by String Theory.…
Observing gravitational lensing effects by Sgr A* with GRAVITY
V. Bozza, L. Mancini
The massive black hole at the Galactic center Sgr A* is surrounded by a cluster of stars orbiting around it. Light from these stars is bent by the gravitational field of the black…
Full orbital solution for the binary system in the northern Galactic disc microlensing event Gaia16aye
Åukasz Wyrzykowski, P. Mróz, K. A. Rybicki +182
Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the…
Space-based Microlens Parallax Observation As a Way to Resolve the Severe Degeneracy between Microlens-parallax and Lens-orbital Effect
C. Han, A. Udalski, C. -U. Lee +23
In this paper, we demonstrate the severity of the degeneracy between the microlens-parallax and lens-orbital effects by presenting the analysis of the gravitational binary-lens eve…
Maximal Acceleration Effects in Reissner-Nordstrom Space
V. Bozza, A. Feoli, G. Papini +1
The dynamics of a relativistic particle in a Reissner-Nordstrom background is studied using Caianiello model with maximal acceleration. The behaviour of the particle, embedded in a…
The OGLE-III planet detection efficiency from six years of microlensing observations (2003 to 2008)
Y. Tsapras, M. Hundertmark, Å. Wyrzykowski +17
We use six years (2003 to 2008) of Optical Gravitational Lensing Experiment III microlensing observations to derive the survey detection efficiency for a range of planetary masses…
pyLIMA : an open source package for microlensing modeling. I. presentation of the software and analysis on single lens models
E. Bachelet, M. Norbury, V. Bozza +1
Microlensing is a unique tool, capable of detecting the 'cold' planets between 1-10 AU from their host stars, and even unbound 'free-floating' planets. This regime has been poorly…
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…
Scalar fluctuations in dilatonic brane-worlds
V. Bozza, M. Gasperini, G. Veneziano
We derive and solve the full set of scalar perturbation equations for a class of five-dimensional brane--world solutions, with a dilaton scalar field coupled to the bulk cosmologic…
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…
Spitzer Microlens Measurement of a Massive Remnant in a Well-Separated Binary
Y. Shvartzvald, A. Udalski, A. Gould +63
We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having (80% probability). A main-sequence…
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…
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…
Alternatives to Schwarzschild in the weak field limit of General Relativity
V. Bozza, A. Postiglione
The metric outside an isolated object made up of ordinary matter is bound to be the classical Schwarzschild vacuum solution of General Relativity. Nevertheless, some solutions are…
Gravitational Lensing by Black Holes
V. Bozza
We review the theoretical aspects of gravitational lensing by black holes, and discuss the perspectives for realistic observations. We will first treat lensing by spherically symme…
The weakly perturbed Schwarzschild lens in the strong deflection limit
V. Bozza, M. Sereno
We investigate the strong deflection limit of gravitational lensing by a Schwarzschild black hole embedded in an external gravitational field. The study of this model, analogous to…
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…
Time Delay in Black Hole Gravitational Lensing as a Distance Estimator
V. Bozza, L. Mancini
We calculate the time delay between different relativistic images formed by black hole gravitational lensing in the strong field limit. For spherically symmetric black holes, it tu…
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…
Microlensing search towards M31
S. Calchi Novati, G. Iovane, A. A. Marino +26
We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31),…
OGLE-2017-BLG-0482Lb: A Microlensing Super-Earth Orbiting a Low-mass Host Star
C. Han, Y. Hirao, A. Udalski +62
We report the discovery of a planetary system in which a super-earth orbits a late M-dwarf host. The planetary system was found from the analysis of the microlensing event OGLE-201…
Euclid Quick Data Release (Q2) -- The Euclid Galactic Bulge Survey
J. -P. Beaulieu, E. Bachelet, M. Gilles +173
The Euclid Quick Data Release Q2 provides an unprecedented deep, wide-field, high-angular-resolution view of the inner Galactic bulge through the Euclid Galactic Bulge Survey (EGBS…
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…